hese are replies to my critics at at Society for German Idealism and Romanticism (SGIR) Author-Meets-Critics session, Pacific APA 2021. -/- Published version of the full symposium is available on SGIR Review's homepage.

Biological sex should be “acknowledged” and “accepted”—but which responses to gender dysphoria might this preclude? Trans-identified people may factually acknowledge their biological sex and regard transition as purely palliative. While generally some level of self-deception and even a high level of nonlying deception of others are sometimes justified, biological sex is important, and there is a nontrivial onus against even palliative, nonsexually motivated cross-dressing. The onus is higher against co-opting the body, even in a minor and/or reversible way, to make (...) a false communication concerning one’s sex. Hardest to defend is the destruction of sexual–reproductive functions and causally downstream functions such as lactation: due to the transcendent nature of sexual–reproductive functions, an appeal to the “principle of totality” here is misplaced. This is not to say that social, and milder medical, transition is absolutely excluded even for severe unmanageable dysphoria, nor that subsequent to any transition, detransition is necessarily required. (shrink)

Though feminists are correct to note that conventional standards of sexiness are oppressive, we argue that feminism should reclaim sexiness rather than reject it. We argue for an aesthetic and ethical practice of working to shift from conventional attributions of sexiness to respectful attributions, in which embodied sexual subjects are appreciated in their full individual magnificence. We argue that undertaking this practice is an ethical obligation, since it contributes to the full recognition of others’ humanity. We discuss the relationship of (...) ethical to aesthetic considerations and argue that the respectful notion of sexiness is a genuinely aesthetic one, even though it does not involve assessment in relation to standards. (shrink)

In the law of rape, consent has been and remains a gendered concept. Consent presumes female acquiescence to male sexual initiation. It presumes a man desires to penetrate a woman sexually. It presumes the woman willingly yields to the man's desires. It does not presume, and of course does not require, female sexual desire. Consent is what the law calls it when he advances and she does not put up a fight. I have argued elsewhere that the kind of thin (...) consent that the law focuses on is not enough ethically and it should not be enough legally to justify sexual penetration. I advocate sexual negotiation, where individuals discuss sexual desires and boundaries and agree to engage in penetration before it occurs, except under circumstances in which the partners have a reasonable basis to assess one another's nonverbal behavior. I argue that not only is verbal consultation about desire ordinarily ethically necessary before most acts of sexual penetration, it should be legally required. Consultation to ascertain sexual desires and boundaries assures that both parties desire penetration. (shrink)

Deadgirl (2008) is based around a group of male teens discovering and claiming ownership of a bound female zombie, using her as a sex slave. This narrative premise raises numerous tensions that are particularly amplified by using a zombie as the film's central victim. The Deadgirl is sexually passive yet monstrous, reifying the horrors associated with the female body in patriarchal discourses. She is objectified on the basis of her gender, and this has led many reviewers to dismiss the film (...) as misogynistic torture porn. However, the conditions under which masculinity is formed here—where adolescent males become “men” by enacting sexual violence—are as problematic as the specter of the female zombie. Deadgirl is clearly horrific and provocative: in this article I seek to probe implications arising from the film's gender conflicts. (shrink)

Unjustifiable assumptions about sex and gender roles, the untamable potency of maleness, and gynophobic notions about women's bodies inform and influence a broad range of policy-making institutions in this society. In December 2004, the U.S. Court of Appeals for the Sixth Circuit continued this ignoble cultural pastime when they decided Everson v. Michigan Department of Corrections. In this decision, the Everson Court accepted the Michigan Department of Correction's claim that “the very manhood” of male prison guards both threatens the safety (...) of female inmates and violates the women's “special sense of privacy in their genitals” and declared that sex-specific employment policies for prison guards is not impermissibly discriminatory. I believe that the Court's decision relies on unacceptable stereotypes about sex, gender and sexuality and it significantly undermines Title VII's power to end discriminatory employment practices. (shrink)

Pressuring someone into having sex would seem to differ in significant ways from pressuring someone into investing in one’s business or buying an expensive bauble. In affirming this claim, I take issue with a recent essay by Sarah Conly (‘Seduction, Rape, and Coercion’, Ethics, October 2004), who thinks that pressuring into sex can be helpfully evaluated by analogy to these other instances of using pressure. Drawing upon work by Alan Wertheimer, the leading theorist of coercion, she argues that so long (...) as pressuring does not amount to coercing someone into having sex, her consent to sex answers the important ethical questions about it. In this essay, I argue that to understand the real significance of pressuring into sex, we need to appeal to background considerations, especially the male-dominant gender hierarchy, which renders sexual pressuring different from its non-sexual analogues. Treating pressure to have sex like any other sort of interpersonal pressure obscures the role such sexual pressure might play in supporting gender hierarchy, and fails to explain why pressure by men against women is more problematic than pressure by women against men. I suggest that men pressuring women to have sex differs from the reverse case because of at least two factors: (1) gendered social institutions which add to the pressures against women, and (2) the greater likelihood that men, not women, will use violence if denied, and the lesser ability of women compared to men to resist such violence without harm. (shrink)

Introductory courses dealing with sex, gender and sexuality often assign excerpts from Thomas Aquinas as an exemplar of the naturalist view. Given that most novice students tend to side against such naturalism uncritically, they need to be exposed to a more charitable account of the biological considerations motivating a stance like Aquinas.’ With that in mind, this article presents accessible arguments aimed at restoring deliberative balance in the classroom.

The sex/gender distinction is a staple of feminist philosophy. In slogan form: sex is “natural,” while gender is the “social meaning” of sex. Considering the importance of the sex/gender distinction—which, here, I neither endorse nor reject—it’s interesting to ask if philosophers working on the metaphysics of sexuality might make use of an analogous distinction. In this paper, I argue that we ought to endorse the sexual orientation/identity distinction. In particular, I argue that the orientation/identity distinction is indispensable to normative (...) explanations regarding LGBTQIA+ oppression and resistance. As a case study, I consider the oppression involved in the gentrification of historic queer neighborhoods. (shrink)

In this article, Bettcher argues that sexual attraction must be reconceptualized in light of transgender experience. In particular, Bettcher defends the theory of “erotic structuralism,” which replaces an exclusively other-directed account of gendered attraction with one that includes a gendered eroticization of self as an essential component. This erotic experience of self is necessary for other-directed gendered desire, where the two are bound together and mutually informing. One consequence of the theory is that the controversial notion of “autogynephilia” is rejected. (...) Another consequence is that the distinction between gender identity and sexual orientation is softened. (shrink)

‘Gender disappointment’ is regularly reported by those whose child’s sex does not match the sex that they, the parent, desired. With symptoms ranging from mere fleeting sadness to documented cases of serious depression, alienation from one’s child, and emotional suffering, it is clear that so-called ‘gender disappointment’ is a serious issue, that has, as yet, seen little philosophical attention (though see Hendl and Browne 2020). In this chapter I explore gender disappointment, not from the perspective of a parent who ended (...) up with the child of the wrong sex at birth, but rather, from the perspective of a different kind of gender disappointment: the transgender person who grew up and only then disappointed their parents by turning out to be the ‘wrong’ gender. This perspective, I argue, reveals a great deal about the shared gender essentialism at the heart of patriarchal and cissexist ideology. Moreover, I will argue that it reveals the underlying propertarian relationship of parents to their children under contemporary capitalism – a troubling relationship that legitimates the treatment of children as objects to be designed and controlled as commodities at the whims of parents. In this way I disagree with Whyman when he writes that “a preference for having a child of one sex over the other should be considered one of those irrational things of which some sense can nevertheless be made – like aesthetic taste” (Whyman 2021, 113-114). I argue, to the contrary, that the desire for a child of one particular gender is not akin to a mere unproblematic aesthetic preference. Instead, and following the rich feminist tradition of thinking about the patriarchal origins of sexual desire, I argue that we must see these desires as troubling reflections of dominant patriarchal and cissexist ideology, underwritten by a particular neoliberal capitalist mode of production. Moreover, we can seek to change those desires. (shrink)

The distinction between heterosexuality and homosexuality does not allow for sufficient attention to be given to the question of non-normative heterosexualities. This paper develops a feminist critique of normative sexuality, focusing on alternative readings of sex and/or gender offered by Beauvoir and Irigaray. Despite their differences, both accounts contribute significantly to dismantling the lure of normative sexuality in heterosexual relations-a dismantling necessary to the construction of a feminist social and political order.

In January 1995, at the age of 22, Annabel Chong (whose real name is Grace Quek), a former pornographic actress/director set a world record (which has since been topped) for having the most number of sex acts, 251 with about 70 men, over a period of about ten hours, for a film called the World’s Biggest Gangbang. Chong claims in subsequent interviews that more than anything else, she did it to challenge the stereotypical notion that female sexuality is passive—that (...) women like to be “seduced, kissed and cuddled, and [are] basically biologically monogamous”. She quips that “if a guy did 251 women in one day . . . everyone would think he’s a real stud”; But if a girl does the same “she’s considered a terrible slut.” This paper is my attempt to investigate what Annabel Chong’s dissent means for feminism: Is Annabel Chong the quintessential feminist, defying an oppressive system, asserting her individuality, redefining the parameters of a gender-determined sexuality? Or is she a victim of her own misguided ideals, objectifying herself in the belief that this affirms her subjectivity, submitting herself to domination to reclaim control, eventually propagating the same oppressive system she professes to end? I want to approach this inquiry using Foucault’s framework of power-discourse-sexuality for two reasons: First, I believe that Foucault’s genealogy of sexuality successfully exploits how sexuality as a discursive construct is used as a technique of control; Second, I believe that Foucault provides us a way of understanding how an individual responds to various systems of control, as well as a framework that explains the many power relations that determine an individual’s mode of existence. However, since in effect, I would be presenting a Foucauldian analysis of the gendered experience of a feminist subject, I find it necessary to first overcome what I consider as theoretical barriers, alluding to the ongoing debate concerning the usefulness of Foucault’s framework for feminists. To address this issue, I will present a brief survey of the criticisms directed to the inadequacy of Foucault’s theory of the subject posed by some notable feminists, as well as the proposed resolutions to them. This also establishes the framework on which I ground my inquiry. My contention is that to some extent these criticisms have already been resolved, and that it is now possible to present an analysis of the gendered experience of the feminist subject using a Foucauldian framework. (shrink)

Is there a choice in sexual orientation? [Wilkerson, William S. : “Is It a Choice? Sexual Orientation as Interpretation”. In: Journal of Social Philosophy 40. No. 1, p. 97–116] argues that sexual desires require interpretation in order to be fully constituted, and therefore sexual orientation is at least partially constituted by choice. [Díaz-León, Esa : “Sexual Orientation as Interpretation? Sexual Desires, Concepts, and Choice”; In: Journal of Social Ontology] critically assesses Wilkerson’s argument, concluding that we still lack a good argument (...) for the claim that choice plays a role in sexual orientation. Here I examine Díaz-León’s response to Wilkerson. I introduce what I call the conceptual act theory of sexual orientation, and argue that even if interpretation were not necessary to constitute sexual desires, it is a necessary element to constitute what we call sexual orientation. However, I conclude that even if we agree that interpretation is involved in sexual orientation, it does not follow that there is a choice involved. (shrink)

The Yogyakarta Principles for the application of human rights to sexual orientation and gender identity define gender identity as “each person’s deeply felt internal and individual experience of gender, which may or may not correspond with the sex assigned at birth, including the personal sense of the body and other expressions of gender, including dress, speech, and mannerisms.” This definition and its acknowledgment within human rights politics is a key step in the fight of trans people for legal protection. Our (...) aim is to analyze this definition both historically and systematically to find out how the Western liberal conception of rights fosters specific trans politics and limits the options for others. Specifically, we claim that political liberalism and the form of subjective rights that it brings about influence concepts of identity and political strategies. While we analyze the limits of the liberal framework, our aim is to think about how it is possible that even within this framework, non-normative bodies and queer identities can be acknowledged and supported through law. (shrink)

What are the effects of circumcision on sexual function and experience? And what does sex—in the sense related to gender—have to do with the ethics of circumcision? Jacobs and Arora (2015) give short shrift to the first of these questions; and they do not seem to have considered the second. In this commentary, I explore the relationship between sex (in both senses) and infant male circumcision, and draw some conclusions about the ongoing debate regarding this controversial practice.

The philosophy of education, being an integrative and anthropologic knowledge, has to perform a prognostic and axiological function, forming a perspective of a world-view genesis of personality and provide theoretical and methodological background for the innovation processes in the education. The forming of harmonious, intellectually developed, creative, conscientious, responsible, purposeful and healthy human personality – these are all the main tasks of the educational system. There are many approaches in performing of such strategic task. One of them, starting from the (...) urgency of a problem of sexual indifference of a modern school education, is presented in a single-sex format of education and is based upon individual approach to the education and upbringing of each and every pupil, taking into account the gender peculiarities of development. In this article we analyze the influence of a single-sex format of education on the process of forming of pupils’ personality, taking into account the age periodization of individual ontogenesis. We developed cognitive, motivational and psychological peculiarities of boys and girls during the periods of childhood and youth. Theoretical comprehension of a need in taking into consideration of the gender characteristics of pupils within the educational process – has been proved on practices, implementing the gender-orientated separate education in schools that demonstrates very positive results. There was made a conclusion about the fact, that the system of gender-orientated separated education has a strong potential of enhancing quality of a pedagogical process and helps to form the personalities of those who study. This can be achieved by taking into account the psychological, physiological and pedagogical peculiarities of boys and girls, by following in the process of educational activities the principals of egalitarianism, nature conformity, self-actualization, creative initiative, democracy and humanism, by creating of an environment, that will be free from impact of gender stereotypes and prejudice. (shrink)

An academic division of labor resulted from the distinction between sex and gender. Sex remained a productive topic (excuse the pun) for biologists, who are interested in the genetic, developmental, and chemical pathways of male/female dimorphism. People in the social sciences and humanities, by contrast, made gender, not sex, the subject of their work. In gender studies, we learn about the ways that men and women “perform” their respective roles—people of male sex can perform as female gender, and vice versa, (...) by adopting modes of speech, dress, behavior, and even values. There is no talk of innate instincts or brain differences in gender studies. The French philosopher Michel Foucault set the agenda when he lamented, as early as 1976, that “the notion of sex made it possible to group together, in an artificial unity, anatomical elements, biological functions, conducts, sensations, and pleasures, and it enabled one to make use of this fictitious unity as a causal principle.” Following this approach, more-recent theorists like Anne Fausto-Sterling and Judith Butler have argued that even the biological categories of sex are just artificial inventions, designed to keep women and intersexed peoples down. Society, they suggest, decides which of us are males and which are females—pushing everyone into rigid binary categories. -/- There are two main arguments that are usually offered in defense of this controversial thesis that sexual dimorphism is political rather than ontological. One is based on a general critique of knowledge (an epistemological argument), and the other on a specific picture of reality (a metaphysical argument). I will offer counterarguments to both. (shrink)

____Race/Sex__ is the first forum for combined discussion of racial theory and gender theory. In sixteen articles, avant-garde scholars of African American philosophy and liberatory criticism explore and explode the categories of race, sex and gender into new trajectories that include sexuality, black masculinity and mixed-race identity.

Ordinary discourse is filled with discussions about ‘sexual orientation’. This discourse might suggest a common understanding of what sexual orientation is. But even a cursory search turns up vastly differing, conflicting, and sometimes ethically troubling characterizations of sexual orientation. The conceptual jumble surrounding sexual orientation suggests that the topic is overripe for philosophical exploration. This paper lays the groundwork for such an exploration. In it, I offer an account of sexual orientation – called ‘Bidimensional Dispositionalism’ – according to which sexual (...) orientation concerns what sex[es] and gender[s] of persons one is disposed to sexually engage, and makes no reference to one’s own sex and gender. (shrink)

In both popular and scholarly discussions, sexual consent is gaining traction as the central moral consideration in how people should treat one another in sexual encounters. However, while the concept of consent has been indispensable to oppose many forms of sexual violence, consent-based sexual ethics struggle to account for the phenomenological complexity of sexual intimacy and the social and structural pressures that often surround sexual communication and behavior. Feminist structural critique and social research on the prevalence of violation even within (...) consensual sex suggest that consent is insufficient to ground responsibility; a more fundamental orientation toward the value of sexual agency provides a better foundation for sexual ethics. Using feminist critical theory, phenomenology, and black feminist thought, this dissertation develops a socially situated and relational notion of sexual agency and diagnoses how such agency is neglected in prevailing discussions of consent in moral philosophy and legal theory. I argue that the ethical question of responsibility to another in a sexual encounter—apart from juridical considerations—should be reframed around the value of each person’s socially situated practices of agency. Preceding and extending beyond the obligation to gain valid consent for an action, responsibility demands adapting one’s intentions and behaviors in response to the wider range of another’s communicative expressions of agency. However, communicative expressions can be ambiguous or overdetermined by social context and cultural norms; they often offer only provisional traces of agency. To address this inherent uncertainty in intimacy, I propose drawing on insights from Emmanuel Levinas about the dynamic, open-ended nature of relationality, responsibility, and communication. Responsibility toward another does not depend on securing certainty about their “yes” or “no,” but requires responding continuously under conditions of uncertainty and ambiguity, adapting behaviors and intentions to make room for another’s agency despite its opacity. (shrink)

This article offers a rereading of Monique Wittig's philosophical writing on sex, gender, and sexuality against some of the major criticisms that have led to limited engagement with her work. I argue that reorienting our understanding of Wittig's lesbian-feminism away from notions of sexuality per se enables us to read her in terms of a larger project that takes aim at the primacy of phallocentrism in how we understand subjectivity. In doing so, I establish and situate three themes (...) in her feminism that have remained largely unremarked upon in contemporary philosophical treatments of her work: domination, utopianism, and polysemy. Part of this reorientation also involves taking seriously the place of language in her philosophy and examining the ways in which she textually expresses the “lesbian” in her literature—a facet similarly underexamined. Although the account of Wittig's philosophy given here is by no means definitive, I aim through this preliminary re-evaluation to provide a richer reading of Wittig's work against prevailing criticism, demonstrate her continuing relevance to feminist thought, and present further avenues of investigation. (shrink)

This paper addresses two related topics: 1. The disanalogies between elective cosmetic practices and sex reassignment surgery. Why does it seem necessary for me – an aging professional woman – to ignore the blandishments of hairdressers wielding dyes and dermatologists wielding acids and scalpels? Why does it not seem equally necessary for a transgendered person to repudiate sex reassignment procedures? 2. The role of the body in identity and agency. How do phenomenological insights regarding the constitution of selfhood in relation (...) to the interplay between the body image and corporeal know-how contribute to an account of the agency of transgendered individuals? Studying several paintings by contemporary feminist artist Jenny Saville has advanced my thinking on these topics. Saville’s imagery is an invaluable aid to reflection on these issues because she uses her painterly technique, which critics often dub “virtuoso,” to represent lived human bodies. In her work, viewers encounter representations of subjectivized, agentic corporeity, as distinct from inert, objectified flesh. Moreover, her sympathetic engagement with nonconformist, devalued bodies helps to reconfigure the standard gestalts of the human body that viewers typically carry with them and thus to convert fear and/or disgust into appreciation and understanding. In this paper, I consider three of Saville’s paintings. Plan, Saville’s self-portrait as a nude female whose body has been prepped for liposuction, conveys the pathos of this procedure. Matrix is a nude portrait of self-described “gender variant visual artist” Del LaGrace Volcano. In the words of one critic Saville’s depiction of Volcano’s nude intersexed body “restores beauty to the primitive [female] genital organ.” Passage, another nude portrait of an intersexed individual, is an image of vibrant sexuality despite the presumptively jarring juxtaposition of breasts and a penis. I argue that conceiving the agentic subject as a rational deliberative capability that uses a conjoined body as the instrument of its will makes it impossible to theorize the agency of transgendered people. In contrast, when agentic subjects are understood as embodied subjects and embodiment is understood as a dimension of practical intelligence, the agency of transgendered individuals is intelligible. (shrink)

In the political discourse regarding gender identity, the concept of biological sex has been weaponised by gender critical commentators to oppose gender affirmation for trans people. Recently, these commentators have appealed to an essentialist model of sex based on anisogamy, or relative gamete size, to argue that one’s sex is an immutable characteristic. I argue that the gender critical argument is unsound. The diverse purposes of sex classification and the complex variability of people’s sexual characteristics show that an essentialist model (...) is untenable. I then consider how a more adequate theoretical framework from the philosophy of biology can accommodate this complexity and capture how sex is classified in relevant contexts. Further implications of the framework are explored which concern the vagueness, polysemy, and mutability of sex. These undercut the gender critical argument and show that the appeal to biological sex fails to undermine gender affirmation for trans people. (shrink)

Despite their purported demographic and institutional decline, White evangelical voters were instrumental in the election of Donald Trump in 2016, and even more so in his 2020 loss. The story of Trump’s electoral successes among Christian voters in the last two elections is in large part the story of religious nationalism—and White Christian nationalism in particular—because Trump personifies the convergence of nationalism-infused forms of messianism and apocalypticism intrinsic to White evangelicalism, which culminate in QAnon cultic ideology. However, these same ethnoreligious/nationalist (...) patterns and logics extend much further back than Trump’s insurgent candidacy. This chapter traces the recurring, resurgent patterns of “zombie nationalism” among White evangelical Christians in the United States over the last half century that emerged in response to periods of significant societal change and certain recurring sociopolitical issues. In particular, alongside established elective affinities around ethnicity (whiteness) and religion (Christianity), this chapter makes the case for incorporating gender and sexual politics as key factors in the articulation and legitimation of religious nationalism in the United States. White Christian nationalism tends to reemerge as a salient political force during periods of rapid social change and diversification, driven by racialized religious grievances symptomatic of Nietzsche’s concept of ressentiment, or the paradoxical internalization and reprojection of a person’s or group’s perceived endangerment, victimhood, and/or suffering, in order to gain power. Drawing on examples of marriage equality and reproductive rights, this chapter demonstrates how an understanding of sexual politics is key to both apprehending and breaking the cyclical reanimation of White Christian nationalism. Escaping the nihilistic impulses driving these cycles will require White evangelicals to develop new hermeneutical tools capable of transforming the exclusionary patterns of racism, ethnocentrism, heteronormativity, and patriarchy that fuel the engine of ressentiment animating zombie nationalism. (shrink)

This investigation focused on relationships among sexual assault, self-blame, and sexual revictimization. Among a female undergraduate sample of adolescent sexual assault victims, those endorsing greater self-blame following sexual assault were at increased risk for sexual revictimization during a 4.2-month follow-up period. Moreover, to the extent that sexual assault victims perceived nonconsensual sex is permitted by law, they were more likely to blame themselves for their own assaults. Discussion focuses on situating victim-based risk factors within sociocultural context.

This chapter presents a positive philosophy of male sexuality: one that is not rooted in so-called toxic masculinity and which is compatible with gender equality. I argue that, for such a sexuality to be possible, respect is the moral baseline. However, the status quo for male sexuality is shaped by white supremacy and heteronormativity. To resist these values, men must do more than merely cross some minimal moral threshold for permissible sex. Rather, they ought to develop a (...) caring character so that they would want to seek out their own and their partner’s (robust) sexual fulfillment. Men ought actively to develop ways to increase pleasure for themselves and their partners. (shrink)

This essay is a case study of the self-destruction that occurs in the work of a social-constructionist historian of science who embraces a radical philosophy of science. It focuses on Thomas Laqueur's Making Sex: Body and Gender from the Greeks to Freud in arguing that a history of science committed to the social construction of science and to the central theses of Kuhnian, Duhemian, and Quinean philosophy of science is incoherent through self-reference. Laqueur's text is examined in detail in order (...) to make the main point; a similar phenomenon in the work of the feminist historian of science Evelyn Fox Keller is then briefly discussed. (shrink)

Postgenderism is an extrapolation of ways that technology is eroding the biological, psychological and social role of gender, and an argument for why the erosion of binary gender will be liberatory. Postgenderists argue that gender is an arbitrary and unnecessary limitation on human potential, and foresee the elimination of involuntary biological and psychological gendering in the human species through the application of neurotechnology, biotechnology and reproductive technologies. Postgenderists contend that dyadic gender roles and sexual dimorphisms are generally to the detriment (...) of individuals and society. Assisted reproduction will make it possible for individuals of any sex to reproduce in any combinations they choose, with or without "mothers" and "fathers," and artificial wombs will make biological wombs unnecessary for reproduction. Greater biological fluidity and psychological androgyny will allow future persons to explore both masculine and feminine aspects of personality. Postgenderists do not call for the end of all gender traits, or universal androgyny, but rather that those traits become a matter of choice. Bodies and personalities in our postgender future will no longer be constrained and circumscribed by gendered traits, but enriched by their use in the palette of diverse self-expression. (shrink)

DIFERENCIAÇÃO SEXUAL -/- Emanuel Isaque Cordeiro da Silva Instituto Agronômico de Pernambuco Embrapa Semiárido -/- • _____OBJETIVO -/- Os estudantes de Veterinária e de Zootecnia estão ligados à disciplina Reprodução Animal, um pelos mecanismos fisiológicos para evitar e tratar as possíveis patologias do trato reprodutivo dos animais domésticos, e outro para o entendimento dos processos fisiológicos visando o manejo reprodutivo e a procriação para a formação de um plantel geneticamente melhorado. Sendo assim, a finalidade do presente trabalho é apresentar os (...) mecanismos que regulam as diferenças sobre o desenvolvimento embrionário relativos à diferenciação e determinação sexual de machos e fêmeas, que também incluem o desenvolvimento dos órgãos envolvidos na reprodução e a origem das diferenças entre ambos os sexos. -/- •____INTRODUÇÃO -/- Os organismos que se reproduzem sexualmente são descendentes de organismos ao qual não existia a diferenciação sexual. Em algum momento da evolução surgiu a reprodução sexual como um mecanismo para incrementar a diversidade genética e facilitar a troca de informações genéticas mediante o material genético da fêmea com o do macho. Devido sua origem comum, na maioria das espécies, tanto os machos como as fêmeas possuem todos os genes necessários para desenvolverem-se em qualquer dos sexos. O que efetivamente faz diferença entre os sexos é a forma e a ordem ao qual se expressam os genes durante o processo de desenvolvimento. A diferenciação sexual é regulada principalmente por mecanismos epigenéticos, mais do que as diferenças genéticas de grande magnitude entre os sexos. Todo o controle epigenético de qualquer processo de desenvolvimento depende basicamente de uma série de expressões gênicas, através da qual a expressão de certa combinação de genes resulta na presença de determinadas proteínas, conhecidas como os fatores de transcrição, que induzem ou reprimem a expressão de outro(os) gene(es), a partir dos quais se produzem novas proteínas, que em certos casos também atuam como fatores de transcrição para outros genes, e assim sucessivamente. Logo, a expressão ou falta de expressão de um gene ao início da série pode resultar em um ladrão totalmente diferente da expressão de outros genes subsequentes, o que pode ocasionar profundas mudanças no processo de desenvolvimento e até a mutações indesejáveis. O padrão predeterminado de expressões gênica relativo a diferenciação sexual na maioria das espécies tanto domésticas quanto selvagens, leva ao desenvolvimento de um dos sexos (o padrão predeterminado dos mamíferos é o sexo feminino). Em consequência, a diferenciação faz com que um indivíduo do sexo oposto exija a expressão de um gene de determinação sexual que desvie a subsequente série de expressões gênica em direção ao dito sexo. Nos mamíferos, a expressão do gene SRY, localizado no cromossomo Y (e portanto ausente nas fêmeas), redige o padrão de diferenciação sexual de sua via pré-estabelecida feminina em direção ao padrão masculino. A existência de uma única diferença genética (presença do gene SRY nos machos e ausentes nas fêmeas), vai se amplificando e termina resultando no desenvolvimento de indivíduos diferentes entre si. Esse é um mecanismo de diferenciação sexual cromossômica. O primeiro passo de uma série de diferenciação sexual, em sentido estrito, não depende nem requer necessariamente a presença de um gene diferente em algum dos sexos. O gene “disparador” da diferenciação sexual pode estar presente em todos os embriões, porém pode expressar-se somente em algum deles, devido a fatores ambientais que formam parte da sua regulação epigenética, isto é, uma determinação sexual ambiental. Em algumas espécies de tartarugas ou de lagartos a expressão ou falta de expressão do gene “disparador”, por exemplo, depende da temperatura existente durante a incubação dos ovos, pelo qual alguns embriões desenvolvem-se como machos e outros como fêmeas, apesar de não existir diferença genética entre eles, simplesmente como consequência da temperatura: a determinação sexual depende da temperatura a que cada um deles foi submetido durante a incubação. Em certas espécies as temperaturas mais elevadas facilitam o desenvolvimento de fêmeas e outras de machos, enquanto que em outras espécies as temperaturas amenas (intermediárias) resultam em machos, e as inferiores como as superiores induzem o desenvolvimento de fêmeas. A existência dessa diversidade indica que a temperatura por si mesma não é a que induz ou a que provoca o desenvolvimento do macho e da fêmea, senão a que atua somente como um regulador inicial da diferenciação sexual. Em outras espécies o fator ambiental que regula a determinação sexual pode ser distinto. A densidade populacional, por exemplo, pode atuar como um regulador. Podemos concluir que a determinação sexual dependente da temperatura ou de outros fatores ambientais estabelece-se antes da determinação sexual cromossômica, a qual evoluiu depois como um método que oferece maior certeza e resultado, já que a proporção de machos e fêmeas não é afetada por mudanças ambientais ou de hábitat. -/- •___FORMAÇÃO INICIAL DA GÔNADA -/- Basicamente em todos os embriões, inicialmente se formam as chamadas gônadas indiferenciadas (com o potencial de desenvolver-se em ovários ou testículos) a partir da invasão das cristas genitais pelas células germinais primordiais, que migram desde seu local de origem no epiblasto, perto do lugar onde o saco vitelino se une com o intestino primitivo e que chegam até às cristas genitais que são engrossamentos de tecido situados na região mesonéfrica do embrião. A migração das células germinais primordiais ocorre muito cedo sobre o processo de desenvolvimento do embrião (dia 26 nos bovinos). Ao chegas as cristas genitais, as células germinativas proliferam-se e se organizam com as células somáticas já existentes nas cristas para ir formando a gônada (figura 1). Para regular essa remodelação e conformação adequada da gônada vários genes se expressam, como o OCT-4 (que aparentemente mantém a totipotencialidade da gônada), assim como o SF-1 (Fator esteroidogênico 1) e o WT-1 (gene associado ao tumor de Wilms). Esses dois últimos genes estimulam a proliferação celular e estabelecimento dos cordões sexuais. Nessa etapa inicial do desenvolvimento todos esses genes se expressam sem distinção de sexo, pelo que a gônada em formação mantém a capacidade de se diferenciar em testículo ou em ovário. -/- Figura 1: migração das células germinais primordiais em direção a crista gonodal. Diferenciação das gônadas femininas e masculinas. Fonte: ZARCO, 2018. -/- •___SEXO CROMOSSÔMICO -/- Têm-se observado que nos mamíferos a determinação sexual depende diretamente dos cromossomos. As fêmeas possuem dois cromossomos sexuais X (um contribuído do óvulo e o outro por um espermatozoide “X”). Os machos, por sua vez, possuem um cromossomo sexual X(proveniente do óvulo) e um cromossomo sexual Y, que provém de um espermatozoide “Y” (figura 2). A metade dos espermatozoides produzidos por um macho são X e a metade Y, isso porque durante a espermatogênese a divisão meiótica provoca que a partir de cada espermatócito primário, célula diploide que por pertencer a um indivíduo macho tem um cromossomo X e um Y, se originem das espermátides haploides a cada um das que eles tocam cromossomos X, e outras espermátides haploides as que eles tocam os cromossomos Y. Dessa forma, de acordo com o tipo do espermatozoide que fertilize o ovócito, se originará um indivíduo com cariótipo feminino “XX” ou um cariótipo masculino “XY” (figura 2). Esse processo é conhecido como sexo cromossômico, ao qual se determina o momento da fertilização. Figura 2: nos mamíferos todos os óvulos produzidos pelas fêmeas possuem um cromossomo sexual X. A metade dos espermatozoides produzidos pelos machos possuem um cromossomo X e a outra metade possui um cromossomo Y. Dependendo do cromossomo presente no espermatozoide que fertilize o óvulo pode-se gerar um indivíduo XX (fêmea) ou um XY (macho). Fonte: ZARCO, 2018. -/- O cromossomo “Y” é uma “invenção” relativamente recente na história da evolução das espécies e do estudo da genética. Surgiu a partir de uma mutação de um cromossomo “X”, que resultou na perda de um de seus braços, que é por onde se originou a morfologia do cromossomo Y. A maioria dos genes presentes no cromossomo Y também existem no cromossomo X; assim mesmo somente alguns genes do cromossomo Y foram evoluídos até ser diferentes dos genes do cromossomo X. Embora os machos possuam um cromossomo que não está presente nas fêmeas, esse mesmo cromossomo não aporta toda a informação genética original. Todos os genes existentes nas fêmeas estão também presentes nos dos machos, já que eles também possuem um cromossomo X. Uma particularidade do cromossomo Y, ao existir somente uma cópia nos machos, é que ele sofre um entrecruzamento com um cromossomo análogo durante o processo de meiose, pelo que o cromossomo Y de um macho é idêntico ao de seu progenitor e ao de seus descendentes, exceto no caso em que ocorra uma mutação espontânea. Em contraste, os cromossomos X das fêmeas (um proveniente do pai e outro da mãe) se entrecruzam durante a meiose, por onde cada óvulo produzido pela fêmea terá uma combinação de alelos distinta em seu cromossomo X. Ao estudar as diferenças presentes na sequência de DNA do cromossomo Y, é possível identificar a distância filogenética entre os indivíduos (quanto mais diferenças existirem entre os cromossomos significa que seu ancestral comum está mais longe). Algo análogo ocorre com o DNA das mitocôndrias, que sempre são aportados pela mãe e nunca sofrem recombinação genética. Gene SRY -/- Um dos poucos genes do cromossomo Y que não possuem correspondência com o cromossomo X é o gene SRY (Sex-determining Region of the Y chromossome – região do cromossomo Y determinante do sexo). Esse gene se expressa somente na gônada em formação nos embriões machos, em particular em células precursoras das células de Sertoli; ele codifica uma proteína da família SOX (SRY-like Box) que é uma família formada por proteínas que possuem um domínio de união ao DNA e que atuam como fatores de transcrição. Ao produzir-se a proteína SRY nas células precursoras das células de Sertoli estimula-se a expressão (transcrição) de outro gene análogo, denominado SOX-9 que, por sua vez, atua como um fator de transcrição que ativa a expressão de outros genes, como o FGF-9 (Fibroblast Growth Factor-9), ou seja ele é o estimulante de ativação dos demais. Os produtos dos genes SOX-9 e FGF-9 iniciam uma cascata de expressões que provocam a diferenciação das células de suporte da gônada indiferenciada (crista genital) em células de Sertoli. Em seguida, essas células dirigem a diferenciação das células intersticiais da crista genital em células de Leydig, o que finalmente resulta na formação de um testículo. Outro dos efeitos da proteína codificada por SOX-9 é um estímulo maior da expressão de seu próprio gene, pelo qual é produzido um ciclo de retroalimentação positiva que favorece a continuidade do processo de formação testicular. Como nos embriões da fêmea não existe o gene SRY, a gônada indiferenciada não é estimulada para expressar os genes SOX-9 nem o FGF-9 nas células de suporte (que nesse caso serão precursoras de células da granulosa). A gônada, em mudança, expressa em forma constitutiva, isto é, sem a necessidade de estimulação, outra cascata de genes que incluem o WNT4 (Wingless-integration Factor 4) e o RAPO1 (Respondina-1), que por sua vez iniciam uma cascata de expressão gênica, a qual provoca a diferenciação das células somáticas da gônada indiferenciada para formação das células da granulosa e células da teca, esse feito conduz, por sua vez, a formação de um ovário. No embrião macho a proteína SOX-9 inibe a expressão dos genes WNT4 e RSPO-1, pelo que a presença do gene SRY, e portanto de SOX-9, inibem a formação de um ovário ao mesmo tempo que estimulam a formação do testículo (figura 3). Em suma, se o embrião possui genótipo XY (um embrião macho), o gene SRY começa a expressar-se sobre as células precursoras da gônada imediatamente depois da formação da mesma, quando os cordões sexuais primários estão se desenvolvendo na medula. A expressão do gene, assim como a presença subsequente das proteínas SOX-9 e FGF-9 estimula a distinção das células de Sertoli e que se organizem os tubos seminíferos a partir dos cordões sexuais primários. Em contrapartida, em um embrião com genótipo XX (fêmea) não existe o gene SRY, pelo qual é impossível que se elevem os níveis das proteínas SOX-9 e FGF-9 e as células precursoras não se diferenciam em células de Sertoli, e portanto os cordões sexuais primários sofrem regressão. Depois de alguns dias, começam a organizar-se os cordões sexuais secundários e as células precursoras iniciam a expressão do gene WNT4, o que leva as mesmas a diferenciar-se em células da granulosa, que serão a base para a conformação dos folículos ovarianos. Se em um embrião XY, macho, a expressão do gene SRY demora, é formada um ovo-testículo devido a que algumas das células somáticas das cristas gonodais começam a expressar o gene WNT4, e a diferenciar-se em células da granulosa, enquanto que em outras a proteína SRY chega a tempo para dirigir a diferenciação para formação das células de Sertoli. No ovário em formação é expressado um gene denominado DAX-1 (Dosage-sensitive Sex Reversal). Esse gene, localizado no cromossomo X, codifica uma proteína que é um membro da família dos receptores nucleares ao que lhe falta o domínio de união ao DNA, pelo que parece atuar no bloqueio de diversos fatores de transcrição, entre os que se encontra o SRY. Como a proteína DAX-1 impede a ação da proteína SRY, um excesso de expressão do gene DAX-1 pode provocar a feminilização gonodal de indivíduos XY, macho, embora tenham SRY. Em condições normais, a expressão adequada do gene DAX-1 não é capaz de evitar a masculinização gonodal de embriões com o gene SRY, daqui o nome de reversão sexual dependente da dose. Figura 3: série de expressão gênica para a determinação gonodal. SRY (Região do cromossomo Y determinante do sexo), SOX-9 (SRY-like Box-9), FGF-9 (Fator de crescimento de fibroblastos-9), WNT4 (Wingless-integration Factor-4), RSPO-1 (Respondina-1). Uma vez que o SRY induz a expressão de SOX-9 na gônada masculina, inicia-se um processo de feedback positivo mediante o qual os níveis de expressão de SOX-9 e FGF-9 vão aumentando, ao mesmo tempo que inibem a expressão de WNT-4 e RSPO-1. Na gônada feminina não se expressam SRY, SOX-9 e nem FGF-9, o que permite que se expressem os genes WNT-4 e RSPO-1, que iniciam uma cascata de sinalização que dirige a formação de um ovário. Fonte: ZARCO, 2018. -/- • ___DIFERENCIAÇÃO SEXUAL DOS GENITAIS -/- Uma vez que se formam os testículos, todo o desenvolvimento subsequente dos órgãos e as características “masculinas” em lugar das femininas é em consequência dos hormônios produzidos pelos testículos em formação, incluindo os andrógenos e o hormônio inibidor dos ductos de Müller. Mediante a ausência de testículos todo o desenvolvimento dos órgãos genitais internos e externos segue um padrão feminino, sem levar em conta se estão presentes os ovários; o que significa a ausência de hormônios gonodais determina que o embrião se desenvolva como fêmea, uma vez que não requerem hormônios ovarianos para desencadear o padrão feminino. Por sua vez, as gônadas masculinas (os testículos), produzem substâncias que desviam o desenvolvimento em direção ao padrão masculino. Sob etapas relativamente rápidas da diferenciação todos os embriões possuem dois pares de dutos sexuais, os dutos de Wolff ou mesonéfricos e os dutos de Müller ou paramesonéfricos (figura 4). A testosterona secretada pelos testículos do feto macho em desenvolvimento atua sobre os dutos de Wolff, o que induz a formação posterior dos dutos deferentes, do epidídimo e das glândulas seminais (figura 4). Figura 4: formação dos órgãos genitais internos a partir dos dutos de Wolff no macho e dos dutos de Müller na fêmea. Fonte: ZARCO, 2018. -/- Os testículos produzem ao mesmo tempo, uma glicoproteína chamada Hormônio Inibidor dos Dutos de Müller (Müllerian Inhibiting Hormone, MIH, também chamado de Anti-Müllerian Hormone, AMH); como o seu nome indica, inibe o desenvolvimento dos dutos de Müller ou paramesonéfricos, provocando sua regressão, que impede a formação dos órgãos genitais característicos da fêmea como os ovidutos, o útero, a cérvix e a porção cranial da vagina (figura 4). O MIH é uma glicoproteína da família dos fatores de crescimento transformativo β (TGFβ). O gene MIH possui locais de união para os produtos dos genes SOX-9 e SF-1, pelo que a presença simultânea de ambos fatores de transcrição é necessária para a secreção do MIH e leva a cabo sua função de iniciação dos dutos de Müller sobre o embrião macho (vale lembrar que nessa etapa tanto a gônada de embriões machos como de embriões fêmeas expressam o gene SF-1, mas somente o macho expressa o SOX-9, para que unicamente esse último produza MIH). O certo é que na gônada do embrião fêmea não se produzem quantidades importantes da proteína SOX-9, além de que se produz a proteína DAX-1, mesma que antagoniza tanto a SOX-9 como a SF-1, todo o qual impede a produção de MIH e resulta no desenvolvimento dos dutos de Müller até a formação dos ovidutos, útero, cérvix e a porção cranial da vagina (figura 4). Assim, na fêmea, ao não haver testículos não circulam concentrações elevadas de andrógenos, o que impedirá o desenvolvimento dos dutos de Wolff, enquanto que os dutos de Müller se desenvolvem já que não haverá a presença do MIH para impedi-lo. O desenvolvimento dos genitais internos e externos femininos não requerem a presença de nenhum hormônio ovariano o que levará a cabo de maneira predeterminada (ou pré-estabelecida) na ausência de testículos. Outra estrutura interna que também se desenvolve de forma distinta nos machos e nas fêmeas é o seio urogenital, que no embrião macho é estimulado pela testosterona para formação da próstata, das glândulas bulbouretrais e da uretra peniana, enquanto que na fêmea forma a porção caudal da vagina. A respeito dos órgãos genitais externos (figura 5), nos embriões de ambos os sexos existem estruturas precursoras chamadas de tubérculo genital e pregas vestibulares. Na fêmea o tubérculo genital da origem ao clitóris e as pregas vestibulares dão origem aos lábios vulvares sem a necessidade da atuação de hormônios ovarianos, já que o padrão “por via pré-estabelecida” é feminino. Em contrapartida, no macho, tanto o tubérculo genital quanto as pregas vestibulares respondem ao hormônio 5α-dehidro-testosterona (DHT), ao qual se formam as células da pele da zona genital a partir da testosterona que é secretada pelos testículos. Para isso existem nas células a enzima 5α-reductasa, que transforma a testosterona em DHT. Uma vez formada, a DHT atua sobre as pregas vestibulares do embrião macho para que se fusionem e formem o escroto (em lugar dos lábios vulvares), e sobre o tubérculo genital para formar o pênis (em lugar do clitóris). Figura 5: estruturas que se desenvolvem nos embriões de cada sexo a partir do seio urogenital, o tubérculo genital e as pregas vestibulares. A cor do né de cada estrutura final corresponde com a cor do nome da estrutura a partir da qual se originou. Fonte: ZARCO, 2018. -/- • ___DIFERENCIAÇÃO SEXUAL DO SISTEMA NERVOSO -/- Existem inúmeras diferenças funcionais entre o sistema nervoso da fêmeas e o do machos, em humanos podem incluir diferenças tão complexas como a maior capacidade de verbal da mulher ou a maior capacidade de orientação espacial do homem. Nessa parte será abordada aquelas diferenças que influenciam diretamente sobre a função reprodutiva, como as diferenças na regulação da secreção de gonadotropinas ou as diferenças na capacidade de comportamento sexual masculino ou feminino. É necessário lembrar que, apesar de que essas diferenças se originem durante um período crítico da vida fetal ou neonatal (dependendo da espécie), geralmente se fazem presentes até que o animal chegue a vida adulta e demonstre obter ou não a capacidade para se comportar como macho ou como fêmea uma vez que é exposto aos hormônios sexuais que são secretada depois da puberdade. Igualmente aos processos acima citados, podemos afirmar que nos mamíferos o padrão pré-estabelecido de comportamento sexual e de secreção de gonadotropinas é o feminino. Se durante os primeiros dias de vida neonatal uma rata fêmea não é exposta a nenhum hormônio gonodal, ao chegar a vida adulta ela terá a capacidade de se comportar como fêmea na presença de estrógenos, assim como de secretar um pico pré-ovulatório de GnRH/LH em resposta aos mesmos (figura 6). Essa rata, portanto, não poderá se comportar como macho embora que em sua vida adulta seja exposta a testosterona. O sistema nervoso do rato macho recém-nascido que é exposto aos andrógenos produzidos pelos testículos, em detrimento, faz com que adquiram o potencial para se comportar como machos em sua vida adulta e que perdem o potencial para ter conduta de fêmeas na presença e/ou administração de estrógenos (processo conhecido como desfeminização do SNC). Se por meios de experimentos injetamos testosterona em uma rata fêmea recém-nascida, essa rata não poderá se comportar como fêmea em sua vida adulta, e passará a se comportar como macho. A castração neonatal de um rato (visando evitar a exposição de seu SNC a andrógenos testiculares), assim mesmo, resultará em sua vida adulta um padrão feminino (SNC feminizado e não masculinizado). O hipotálamo das ratas adultas possui uma área em que o número, características e densidade dos corpos neurais difere em machos e fêmeas, essa área é denominada como “núcleo sexualmente dimórfico do hipotálamo”, e tem demonstrado que quando as ratas são tratadas com testosterona na vida neonatal, a morfologia de seu núcleo sexualmente dimórfico será masculinizado em sua vida adulta, enquanto que a castração neonatal de ratos resulta em um núcleo sexualmente dimórfico feminizado em sua vida adulta. Isso significa que a exposição ou não a testosterona na vida neonatal é o que determina que tipo de núcleo sexualmente dimórfico se desenvolverá, o que por sua vez está relacionado com o tipo de conduta que o animal poderá expressar em sua vida adulta. Não deixa de ser um paradoxo que ao injetar uma dose elevada de estrógenos nos primeiros dias de vida de uma rata, os núcleos sexualmente dimórficos da mesma se desenvolverão como macho e em sua vida adulta seu potencial de conduta estará masculinizado e desfeminizado. O hormônio “feminino” conhecido como estradiol, masculiniza o hipotálamo e a conduta do animal. Logo, se a rata neonatal for exposta a injeção de andrógeno não-aromatizado (que não pode ser transformado em estrógenos pelas células) ela não se masculiniza. A masculinização e desfeminização dos ratos ou das ratas tratados com testosterona, na realidade, não são provocados pela própria testosterona, senão pelos estrógenos que se formam dentro dos neurônios quando absorvem a testosterona do sangue e a aromatizam para transformá-la em estrógenos (figura 6). Figura 6: desfeminização e masculinização do sistema nervoso central por meio da testosterona, que quando não absorvida pela α-fetoproteína pode entrar nos neurônios, onde se aromatizam para serem transformados em estrógenos, hormônio que é responsável pela desfeminização. Fonte: ZARCO, 2018. Por que as ratas, que possuem ovários funcionalmente produtores de estrógenos, não se masculinizam? A resposta está em uma proteína denominada α-fetoproteína que circula em altas concentrações nos fetos e nos recém-nascidos. Essa proteína possui a capacidade de unir-se aos estrógenos, ao qual impede seu entrada nas células. Os ratos, em desenvolvimento, produzem testosterona, no entanto não possui afinidade pela α-fetoproteína, o que permite com que ela circule livremente. Ao chegar ao SNC, a testosterona (que não foi absorvida) pode entrar nos neurônios e dentro deles se aromatizam e transformam-se em estrógenos, que finalmente masculinizam o SNC. A diferenciação sexual do hipotálamo depende, em síntese, da presença ou ausência dos testículos, o que permite que se produza ou não o hormônio testosterona que pode não ser absorvida por parte da α-fetoproteína, transformar-se em estrógenos e masculinizar o SNC. -/- •___CONCLUSÃO -/- Nos mamíferos todo o processo que se requerem para o desenvolvimento de um macho depende da existência de somente um gene do cromossomo Y, o gene SRY; a ausência desse gene resulta no desenvolvimento de uma fêmea. A presença ou ausência do gene SRY determina, então, a cadeia de eventos morfogênicos que ocorrerá em sua expressão ou não, para desenvolver todos os órgãos e características de um macho ou de uma fêmea. Por essa razão, os indivíduos com uma monossomia XOA (síndrome de Turner) são fêmeas (por não possuir o cromossomo Y nem o gene SRY), enquanto que os indivíduos triploides XXY (síndrome de Kleinefelter) são machos embora possuam dois cromossomos X. Em algumas espécies, no entanto, têm-se identificado machos que são cromossomicamente XX; nesses casos é determinado invariavelmente que por ser um erro durante a meiose a região do cromossomo Y em que reside o gene SRY tem sido transloucada ao cromossomo X. Da mesma forma, em alguns casos tem sido encontrado fêmeas com cariótipo XY; que nelas se identifica uma mutação inabilitante do gene SRY. Isso demonstra experimentalmente que por meio da engenharia genética é possível produzir machos com cariótipo XY mas com o gene SRY eliminado (knockout). Como é de se esperar, esses machos desenvolvem ovários e todos seus órgãos genitais, tanto internos quanto externos, e se desenvolvem como fêmeas. Os machos cromossomicamente XX transgênicos aos que se insertam uma cópia do gene SRY, desenvolvem testículos e um fenótipo masculino, embora sejam estéreis por causa da ausência de alguns genes do cromossomo Y que são necessários para a realização de uma espermatogênese normal. As falhas nos mecanismos de diferenciação sexual podem, diretamente, ocasionar anormalidades como as observadas nas bezerras Freemartin, que são bezerras originadas de uma gestação gemelar em que seu gêmeo era macho. O que sucede é que na espécie bovina, quando há uma gestação gemelar, é produzido um certo grau de anastomose entre as placentas dos fetos, o que permite a troca de sangue e de células entre ambos. Os produtos recebem, então, algumas células de seu gêmeos, que encontram seu lugar no órgão correspondente e se integram a ele. No caso particular das gônadas, quando o ovário primitivo de um embrião fêmea é colonizado por algumas células gonodais de seu gêmeo macho, essas células expressam o gene SRY, o que fará com que essa região da gônada se diferencie como testículo. Como resultado, se desenvolve um ovo-testículo (com maior ou menor proporção de tecido testicular dependendo do grau de colonização da gônada em formação por células provenientes do gêmeo macho). Ademais, ao haver certa quantidade de tecido testicular produtor de MIH, circularão sobre o feto fêmea níveis desse hormônio que, embora baixos, afetarão o desenvolvimento normal dos dutos de Müller, fazendo com que as bezerras Freemartin possuam genitálias internas ausentes ou pouco desenvolvidas. Os andrógenos produzidos pelas zonas de tecido testicular, por fim, são suficientes para causar um certo grau de masculinização, que se manifesta como um clitóris mais grande que o normal ou um desenvolvimento corporal masculinizado. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- ARNOLD, Arthur P.; CHEN, Xuqi; ITOH, Yuichiro. What a difference an X or Y makes: sex chromosomes, gene dose, and epigenetics in sexual differentiation. In: Sex and gender differences in pharmacology. Springer, Berlin, Heidelberg, 2013. p. 67-88. CUNNINGHAM, James. Tratado de fisiologia veterinária. Elsevier Health Sciences, 2011. DERIVAUX, Jules; BARNABÉ, Renato Campanarut. Reprodução dos animais domésticos. Zaragoza: Acribia, 1980. DA SILVA, Emanuel Isaque Cordeiro. Desenvolvimento Embrionário e Diferenciação Sexual nos Animais Domésticos. Disponível em:. Acesso em: Julho de 2020. HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. HIDALGO, C. Galina et al. Reproducción de animales domésticos. México: Limusa, 2008. MACLAUGHLIN, David T.; DONAHOE, Patricia K. Sex determination and differentiation. New England Journal of Medicine, v. 350, n. 4, p. 367-378, 2004. MCCARTHY, Margaret M.; ARNOLD, Arthur P. Reframing sexual differentiation of the brain. Nature neuroscience, v. 14, n. 6, p. 677, 2011. PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. Academic Press, 2014. REY, Rodolfo. Diferenciación sexual embrio-fetal: De las moléculas a la anatomía. Revista chilena de anatomía, v. 19, n. 1, p. 75-82, 2001. SENGER, P. L. Embryogenesis of the pituitary gland and male or female reproductive system. In. Pathways to Pregnancy and Parturition. Current Conception Inc, v. 1, p. 8-76, 1997. ZARCO, L. Diferenciación sexual. In. PORTA, L. R.; MEDRANO, J. H. H. Fisiología reproductiva de los animales domésticos. Cidade do México: FMVZ-UNAM, 2018. -/- REALIZAÇÃO -/- . (shrink)

A feminist reading of how Heidegger may have responded to an unanswered questioned he posed in 1923, "Problem: What is woman?" while using his thought to better understand how contemporary society replies to questions in the realms of law, bioethics, pedagogy, and politics.

This paper examines constitutional issues concerning same-sex marriage. Although same-sex relations concern broader ethical issues as well, I set these aside to concentrate primarily on legal questions of privacy rights and equal protection. While sexual orientation is neither a suspect classification like race, nor a quasi classification like gender, there are strong reasons why it should trigger heightened scrutiny of legislation using sexuality as a standard of classification. In what follows, I argue that equal-protection doctrine is better suited for (...) including same-sex couples where legal benefits and burdens of marriage are at stake. (1) I reconstruct arguments from privacy and the controversial ruling of Bowers v. Hardwick but discount this strategy for problematic legal reasons. (2) In order for equal protection to apply, sexual orientation must meet the criteria of suspect classification that the Court has established. (3) Since sexual orientation meets these criteria, heightened scrutiny should be applied to such legislation on equal-protection grounds. (4) Finally, I rely on some familiar Rawlsian arguments of public justification that demonstrate why this extension of marriage rights is consistent with basic constitutional principles. (shrink)

In the consolidated cases Altitude Express v. Zarda, Bostock v. Clayton County, and R.G. & G.R. Harris Funeral Homes v. EEOC, the Supreme Court will decide whether or not Title VII prohibits discrimination on the basis of sexual orientation or gender identity. Although the parties disagree as to the appropriate formulation of a but-for test to determine whether or not there was a discriminatory outcome, all parties do agree to the use of such a test, which asks “whether the evidence (...) shows ‘treatment of a person in a manner which but for that person’s sex would be different.’” City of Los Angeles, Dep’t. of Water and Power v. Manhart, 435 U.S. 702, 711 (1978). However, but-for tests confuse more than they clarify the inquiry; a discriminatory outcome cannot be explained by appeal to just a discrete characteristic of a particular person. Individuals are not discriminated against because of these characteristics per se. Rather, they are discriminated against because of the social meanings and expectations that attach to these characteristics. Beyoncé and Taylor Swift illustrate the difference between individual-level causation and social explanation in two separate songs, “If I Were a Boy” and “The Man.” The explanation for why the counterfactual ‘male’ Beyoncé and Swift are evaluated differently than their current ‘female’ versions does not lie in individual-level features considered apart from the social world, but in social-level roles and expectations associated with those features. For this reason, a social explanation test—one that asks whether the social meanings of sex characteristics, rather than the characteristics per se, explain the outcome in question—is more suitable for determining whether or not Title VII has been violated. (shrink)

Gender, race, and sexuality are not just identities; they are also systems of social organization – i.e., systems of privilege and oppression. This article addresses two main ways privilege and oppression (e.g., racism, misogyny, heteronormativity) are relevant topics in and for philosophical aesthetics: (i) the role of the aesthetic in privilege and oppression, and (ii) the role of philosophical aesthetics, as a discipline and a body of texts, in constructing and naturalizing relations of privilege and oppression (i.e., white heteropatriarchy). (...) The first part addresses how systems of privilege and oppression use the aesthetic. I will discuss various ways race, gender, and sexuality, as both embodied identities and broader social institutions, work with and through “the aesthetic”. The second part addresses racism and (hetero) sexism in the discipline of aesthetics. Both in its history and its present practice aesthetics’apparent neutrality on questions of privilege and oppression is actually evidence of its investment in systems of privilege and oppression. (shrink)

What’s important about ‘coming out’? Why do we wear business suits or Star Trek pins? Part of the answer, we think, has to do with what we call agential identity. Social metaphysics has given us tools for understanding what it is to be socially positioned as a member of a particular group and what it means to self-identify with a group. But there is little exploration of the general relationship between self-identity and social position. We take up this exploration, developing (...) an account of agential identity—the self-identities we make available to others. Agential identities are the bridge between what we take ourselves to be and what others take us to be. Understanding agential identity not only fills an important gap in the literature, but also helps us explain politically important phenomena concerning discrimination, malicious identities, passing, and code-switching. These phenomena, we argue, cannot be understood solely in terms of self-identity or social position. (shrink)

British art historian Charles Harrison presumes the existence of a patriarchal world with power in the hands of men who dominate the representation of women and femininity. He applauds the ground-breaking work of feminist theorists who have questioned this imbalance of power since the 1970s. He stops short, however, of accepting their claims that all women have been represented by male artists as images of “utter passivity” (p. 4), routinely reduced by the male gaze to the status of exploited sexual (...) objects, or that women’s subjectivity is eroded by the visual treatment they receive at the hands of male artists such as Manet and Picasso. He wants to show that what is depicted in the picture plane by the (typically male) artist and enjoyed by the (typically male) spectator is more nuanced than just a simple privileged understanding between two men. He adds a third (and possibly fourth or more) party to the mix when he significantly redefines and expands our concept of the gaze: “A gaze may also be conceived of as a function of a painting’s represented content” (p. 9). In other words, a gaze may be “addressed outward by a represented figure,” and regardless of who and where, “the assumption conveyed by the term [‘gaze’] is that some differential and usually asymmetrical relation will be at stake in any exchange between one who directs the gaze and another at whom it is directed. In fact, it is just this difference—in age, in sex, in class, in interest, in power —that the operation of the gaze tends to mark” (p. 9). Referring to a woman depicted within the picture plane, he asks us to consider, “What does it feel like to look like this?” (p. 21) in order to entertain our many emotional responses and interpretations. When he adds, “What does it feel like to whom?” the sexual difference of the spectator also clearly comes into play. (shrink)

‘What is ‘sexual orientation’ for?’ is a question we need to answer when addressing a more seemingly basic one, ‘what is sexual orientation?’. The concept of sexual orientation is grounded in the concepts of sex and/or gender since it refers to the sex or gender of the individuals one is sexually attracted to. Typical categories of sexual orientation such as ’heterosexual’, ‘homosexual’, and ‘bi-sexual’ all rely on a sex or gender binary. Yet, it is now common practice to recognize sex (...) and gender categories that transcend the binary. Should our sexual orientation categories be revised to reflect sex and gender diversity? Drawing on the example of pansexuality, I argue that they should. The reason is that one aim of reconstructing the concept of sexual orientation—in addition to the epistemic goal of understanding— should also be political: it should make it easier to argue for the protection of those who have been marginalized or discriminated against because their sexual attraction is other than heterosexual. (shrink)

Browne 1 (this issue ) argues that what may appear to be a benevolent practice-disclosing the sex of a fetus to expecting parents who wish to know-is in fact an epistemically problematic and, as a result, ethically questionable medical practice. Browne worries that not only will the disclosure of fetal sex encourage sex-selective abortions (an issue we will not take up here), but also that it will convey a misleading and pernicious message about the relationship between sex and gender. More (...) specifically, she contends that the practice of disclosure is problematic because (1) it purports to establish the gender of the developing baby based on information about the baby's sex, whereas this is not a warranted inference because while sex is determined by biological factors, gender is determined by social factors and (2) it conflates (biological) sex with (social) gender or encourages such conflation or reduction and thereby promotes 'essentialistic' thinking about gender that is closely linked to sexism and social injustice. If (1) is true, then disclosing fetal sex amounts to misinforming or misleading prospective parents-and since misinforming patients is wrong, the act of disclosing is also wrong. However, beyond the wrongs of misinforming patients, the practice also perpetuates the harms associated with a rigidly gendered society through endorsing the message in (2), thus lending the authority of the medical profession to the gender-essentialist ideas that have underpinned, and continue to drive, sexism and social injustice. This analysis leads Browne to recommend that clinicians be prohibited from informing parents about the sex of their developing fetus. -/- We agree with Browne that gender essentialism-the notion that 'femaleness' and 'maleness' carve out distinct natural classes with innate, immutable properties-is not only a false metaphysical thesis, but also a pernicious idea insofar as the sexist attitudes it fosters motivate policies that systematically violate the human rights of women, as well as those of the LGBTQ community. However, we do not think that the disclosure of fetal sex misinforms prospective parents about the gender of their baby, nor do we believe that such disclosure presupposes or promotes gender essentialism properly understood. (shrink)

“I am only what I make myself to be”, Fichte tells us. In this paper, I outline Fichte’s views on sex, marriage and gender, with two aims. Firstly, to elucidate an aspect of his moral theory which has received little attention, and secondly to argue that Fichte’s distinctive stance on selfhood, freedom, and normativity lead to a revisionary account of gender expression and identity, where people can freely carve out their own identity, irrespective of “nature”. In this paper, I therefore (...) outline Fichte’s own views, highlighting what I see as a tension in the texts between essentialism and antiessentialism about gender, before reconstructing a neo-Fichtean view which foregrounds the anti-essentialist aspect. (shrink)

In January 2024, non-consensual deepfakes came to public attention with the spread of AI generated sexually abusive images of Taylor Swift. Although this brought new found energy to the debate on what some call non-consensual synthetic intimate images (i.e. images that use technology such as AI or photoshop to make sexual images of a person without their consent), female celebrities like Swift have had deepfakes like these made of them for years. In 2017, a Reddit user named “deepfakes” posted several (...) videos in which he had used opensource machine learning tools to swap the faces of female celebrities on to the faces of female porn actors, displaying what appeared to be live video footage of the celebrity engaging in sex acts she never engaged in. Since that time, deepfake technology has advanced astronomically. What once were choppy sexualized videos are now nearly flawless videos that can be difficult to distinguish from a real video. According to recent research on deepfakes by Sensity AI, this technology has been used primarily on women to create sexual videos. These women’s sexual autonomy has been co-opted for the purposed of gratifying men’s sexual pleasure, but have also been used in campaigns to delegitimize and humiliate female journalists and politicians. In Canada, civil and criminal legislation has addressed the non-consensual distribution of intimate images, but in only a few provinces – British Columbia, New Brunswick, Prince Edward Island and Saskatchewan – does this offence include altered images that could include deepfakes. This paper explores the evolution of synthetic technology such as AI image generators and Canada’s legal responses to the non-consensual sharing of intimate images. (shrink)

How should we react to the development of sexbot technology? Taking their cue from anti-porn feminism, several academic critics lament the development of sexbot technology, arguing that it objectifies and subordinates women, is likely to promote misogynistic attitudes toward sex, and may need to be banned or restricted. In this chapter I argue for an alternative response. Taking my cue from the sex positive ‘feminist porn’ movement, I argue that the best response to the development of ‘bad’ sexbots is to (...) make better ones. This will require changes to the content, process and context of sexbot development. Doing so will acknowledge the valuable role that technology can play in human sexuality, and allow us to challenge gendered norms and assumptions about male and female sexual desire. This will not be a panacea to the social problems that could arise from sexbot development, but it offers a more realistic and hopeful vision for the future of this technology in a pluralistic and progressive society. (shrink)

Irigaray’s engagement with Aristotelian physics provides a specific diagnosis of women’s ontological and ethical situation under Western metaphysics: Women provide place and containership to men, but have no place of their own, rendering them uncontained and abyssal. She calls for a reconfiguration of this topological imaginary as a precondition for an ethics of sexual difference. This paper returns to Aristotelian cosmological texts to further investigate the topologies of sexual difference suggested there. In an analysis both psychoanalytic and phenomenological, the paper (...) rigorously traces a teleological and oedipal narrative implicit in the structure of the Aristotelian cosmos, in which desire for the mother is superseded by love for the father. Further, the paper argues that this narrative is complicated by certain other elements in the Aristotelian text—aporias involving the notion of boundary and the relationship between space and time, the fallenness of the feminine, and the ineliminably aleatory qualities of matter. The paper concludes that such elements may provide material for disrupting this teleology of gender, opening onto not merely an ethics of sexual difference, but providing space and place for a proliferation of non-normative, queer, transgender and intersex modes of sexed and gendered subjectivity. (shrink)

Representing the best popular and scholarly contributions to transgender/ sex studies, and with their mutual concern with female-to-male sex and gender crossing (among other topics), these three books mark an important shift in scholarship on gender and sexuality. Trans studies has reached a level of autonomy and sophistication that firmly establishes it as a field with its own theoretical and political questions. Of course, connections to feminist and queer theory are still very apparent in these texts, and all three (...) authors are committed—to varying degrees—to reading trans identities against the backdrop of male dominance and heteronormativity. It’s no longer enough, however, for feminist readers to dismiss the projects of trans theorists and activists as epiphenomenal to feminist discourses or even queer theory, or to view trans studies as an optional extra in discussions of sex and gender. These books represent the best arguments against this position, and thus offer a new challenge to the inclusivity, scope, and terms of “women’s studies.”. (shrink)

People often assume that everyone can be divided by sex/gender (that is, by physical and social characteristics having to do with maleness and femaleness) into two tidy categories: male and female. Careful thought, however, leads us to reject that simple ‘binary’ picture, since not all people fall precisely into one group or the other. But if we do not think of sex/gender in terms of those two categories, how else might we think of it? Here I consider four distinct models; (...) each model correctly captures some features of sex/gender, and so each is appropriate in some contexts. But the first three models are inadequate when tough questions arise, like whether trans women should be admitted as students at a women’s college or when it is appropriate for intersex athletes to compete in women’s athletic events. (‘Trans’ refers to the wide range of people who have an atypical gender identity for someone of their birth-assigned sex, and ‘intersex’ refers to people whose bodies naturally develop with markedly different physical sex characteristics than are paradigmatic of either men or women.) Such questions of inclusion and exclusion matter enormously to the people whose lives are affected by them, but ordinary notions of sex/gender offer few answers. The fourth model I describe is especially designed to make those hard decisions easier by providing a process to clarify what matters. (shrink)

Many philosophers believe that our ordinary English words man and woman are “gender terms,” and gender is distinct from biological sex. That is, they believe womanhood and manhood are not defined even partly by biological sex. This sex/gender distinction is one of the most influential ideas of the twentieth century on the broader culture, both popular and academic. Less well known are the reasons to think it’s true. My interest in this paper is to show that, upon investigation, the arguments (...) for the sex/gender distinction have feet of clay. In fact, they all fail. We will survey the literature and tour arguments in favor of the sex/gender distinction, and then we’ll critically evaluate those arguments. We’ll consider the argument from resisting biological determinism, the argument from biologically intersex people and vagueness, the argument from the normativity of gender, and some arguments from thought experiments. We’ll see that these arguments are not up to the task of supporting the sex/gender distinction; they simply don’t work. So, philosophers should either develop stronger arguments for the sex/gender distinction, or cultivate a variety of feminism that’s consistent with the traditional, biologically-based definitions of woman and man. (shrink)

Erotic Nights of the Living Dead (1980) may have featured both animated corpses and hardcore sex scenes, but only recently have Re-Penetrator (2004) and Porn of the Dead (2006) managed to fully eroticise the living dead, allowing these creatures to engage in intercourse. In doing so, the usually a-subjective zombie is allotted a key facet of identity - sexuality. This development within the sub-genre needs accounting for outside of the contexts of porn studies, where it has only been briefly (...) touched upon in relation to its "extremity". -/- Moreover, the gendering of the undead opens a discussion which expand the horizons of zombie studies away from the overt critiques of capitalism, race and psychoanalysis that have pervaded analyses of these narratives. The dichotomy of binary oppositions so often associated with psychoanalytic approaches dictates that "passive (non-phallic) = female", and "active (phallic) = male". In these terms, the zombies are feminine - soft-bodied and passive, despite their murderous intent (which has been accounted for, by Barabara Creed (1993) amongst others, by invoking the vagina-dentata motif). Humans (active) are deemed masculine, not least since they tend to dispatch zombies with "phallic guns". Taking this logic to an extreme, the zombie may be read as allegorising feminism: the "feminised" figures (zombies) become fearsome in their will to exert themselves despite their seeming disempowerment in the face of "masculine" hegemony. Ultimately, by grouping together as a force, they overthrow or at least significantly damage that "normality" (an ideological paradigm usually read in terms of race, class and economics). (shrink)

In response to three papers about sex and disability published in this journal, I offer a critique of existing arguments and a suggestion about how the debate should be reframed going forward. Jacob M. Appel argues that disabled individuals have a right to sex and should receive a special exemption to the general prohibition of prostitution. Ezio Di Nucci and Frej Klem Thomsen separately argue contra Appel that an appeal to sex rights cannot justify such an exemption. I argue that (...) Appel’s argument fails, but not for the reasons Di Nucci and Thomsen propose, as they have missed the most pressing objection to Appel’s argument: Appel falsely presumes that we never have good reasons to restrict someone’s sexual liberty rights. More importantly, there is a major flaw in the way that all three authors frame their positive accounts. They focus on disability as a proxy for sexual exclusion, when these categories should be pulled apart: some are sexually excluded who are not disabled, while some who are disabled are not sexually excluded. I conclude that it would be less socially harmful and more productive to focus directly on sexual exclusion per se rather than on disability as a proxy for sexual exclusion. (shrink)

The irony of the rejection of the sex/gender distinction is that it renders sociology per se an impossible enterprise. For it is my submission that, contra Hood-Williams (1996) and others, the biological and the social constitute distinct, irreducible levels of reality: to conflate (in a ‘downwards’ or ‘upwards’ direction) the two levels is immediately to render analysis of their relative interplay at best intractable. It is indeed arguable that Hood-Williams is not so much concerned with (rightly) rejecting the so-called ‘additive’ (...) approach to the biological and the social where the biological base is seen a priori as immutable, but more fundamentally with rejecting the necessary dualism of nature and culture (ie the biological and the social). In contradistinction, a realist defence of the sex/gender distinction will be made, involving critical reference to various major writers in the field and offering a brief but tentative discussion of the provenance of gender. (shrink)