During the first years of the post-war era, many French scientists travelled in the United States. As they looked for a reference to be used in rebuilding their own scientific landscape, their diaries say as much about the rise of the American biomedical complex as they do about their perception of research in the country. In order to illustrate how the French biologists adopted, competed with, or challenged the American model and how transatlantic exchanges played a critical role in the (...) molecularization of the life sciences, this paper presents three trajectories of laboratories. These include the services respectively led by P. Lépine and J. Monod at the Pasteur Institute, and G. Schapira’s biochemical research unit at the Hôpital des Enfants Malades. The three studies document the massive transatlantic circulation of materials, techniques, instruments, and people during the scientific reconstruction. The reconstruction however produced highly differentiated characters each operating in his own niche: the biotechnological inventor, the neo-clinician, and the fundamental biologist. The comparison situates the rise of molecular biology within the context of a rapidly expanding biomedical research system. It will help in understanding how, in contrast to the American situation, a logic of “demedicalization” became in France a means for developing biology at the molecular level. (shrink)

In 1936, Frank Macfarlane Burnet published a paper entitled "Induced lysogenicity and the mutation of bacteriophage within lysogenic bacteria," in which he demonstrated that the introduction of a specific bacteriophage into a bacterial strain consistently and repeatedly imparted a specific property – namely the resistance to a different phage – to the bacterial strain that was originally susceptible to lysis by that second phage. Burnet's explanation for this change was that the first phage was causing a mutation in the bacterium (...) which rendered it and its successive generations of offspring resistant to lysogenicity. At the time, this idea was a novel one that needed compelling evidence to be accepted. While it is difficult for us today to conceive of mutations and genes outside the context of DNA as the physico-chemical basis of genes, in the mid 1930s, when this paper was published, DNA's role as the carrier of hereditary information had not yet been discovered and genes and mutations were yet to acquire physical and chemical forms. Also, during that time genes were considered to exist only in organisms capable of sexual modes of replication and the status of bacteria and viruses as organisms capable of containing genes and manifesting mutations was still in question. Burnet's paper counts among those pieces of work that helped dispel the notion that genes, inheritance and mutations were tied to an organism's sexual status. In this paper, I analyze the implications of Burnet's paper for the understanding of various concepts – such as "mutation," and "gene," – at the time it was published, and how those understandings shaped the development of the meanings of these terms and our modern conceptions thereof. (shrink)

In 1936, Frank Macfarlane Burnet published a paper entitled “Induced lysogenicity and the mutation of bacteriophage within lysogenic bacteria,” in which he demonstrated that the introduction of a specific bacteriophage into a bacterial strain consistently and repeatedly imparted a specific property – namely the resistance to a different phage – to the bacterial strain that was originally susceptible to lysis by that second phage. Burnet’s explanation for this change was that the first phage was causing a mutation in the bacterium (...) which rendered it and its successive generations of offspring resistant to lysogenicity. At the time, this idea was a novel one that needed compelling evidence to be accepted. While it is difficult for us today to conceive of mutations and genes outside the context of DNA as the physico-chemical basis of genes, in the mid 1930s, when this paper was published, DNA’s role as the carrier of hereditary information had not yet been discovered and genes and mutations were yet to acquire physical and chemical forms. Also, during that time genes were considered to exist only in organisms capable of sexual modes of replication and the status of bacteria and viruses as organisms capable of containing genes and manifesting mutations was still in question. Burnet’s paper counts among those pieces of work that helped dispel the notion that genes, inheritance and mutations were tied to an organism’s sexual status. In this paper, I analyze the implications of Burnet’s paper for the understanding of various concepts – such as “mutation,” and “gene,” – at the time it was published, and how those understandings shaped the development of the meanings of these terms and our modern conceptions thereof. (shrink)

The first part of this paper has shown that the development of regulatory genetics and the lactose operon model stemmed from laboratory cultures rooted in local traditions. A "physiological" culture may be recognized in the Pasteurian context. The institutional continuity provided the basis for a tenuous link between Pasteur, Lwoff, and Monod. My claim is that the "national" value of regulatory and physiological genetics is an artifact produced in the course of the legitimization process accompanying the institutionalisation of the discipline. (...) In the 1960s, the lactose operon model was turned into a "flag-object," a symbol of the new culture. The work done by the Pasteurian group became therefore the most important, if not the only, exemplar of molecular biology in France.The second part o f the paper described the origins of general patterns that dominated the building of molecular biology in France. The study of the relationships between molecular biologists and biochemists or immunologists revealed the existence of alternatives to the development of operon research, or to the convergence with molecular biology. Both examples uncover specific paths leading to achievements that might be viewed as international trends: the expansion of RNA and translation studies, and the development of cellular immunology. They illustrate two possible patterns of linking local settings and disciplinary traditions: an oligopolistic situation where a few groups or one institution dominate an entire field, and the emergence of "collective" trends through collaboration networks or schools. (shrink)

Many historical studies have been devoted to the French school of molecular biology, in particular to the work of Jacques Monod on adaptive enzymes. By focusing on Francois Jacob's studies on lysogeny between 1950 and 1960, we intend to redress the imbalance of historiography, as well as proposing a more fruitful point of view for understanding the relative importance of international contacts and local traditions in the genesis of the operon model.Elie Wollman and Jacob's work on temperate bacteriophages rendered respectable (...) a system that had been considered an artefact for more than two decades. They did this firstly by modelling their studies on those of the US phage group and secondly by basing these studies on a complex vision of the relations between bacteria and bacteriophages. The interaction between bacteria and temperate bacteriophages was considered ab initio as a biochemical process, the mechanisms of which would eventually be characterized. It was also considered as a ''normal'' phenomenon that could be used as a model to understand the process of differentiation, as well as the role of viruses in diseases and cancer. The temperate bacteriophage was a model system that was far more epistemologically open and, for this reason, in a sense more productive than the virulent phage studied by the US phage group. (shrink)

Although it has not been much noticed, reproduction is the central theme of François Jacob’s important history of biology, La logique du vivant (The Logic of Life). In a book ostensibly devoted to heredity, this molecular biologist had reproduction integrate levels of organization from organisms to molecules and play a major role in each historical transition between them, not just in the influential argument for a shift “from generation to reproduction.” Moreover, I claim, La logique was the first general history (...) of (research on) reproduction. Earlier histories had tackled only aspects of generation and reproduction; none historicized the latter. Jacob’s innovation came out of the rising prominence of reproduction in neo-Darwinist studies of populations and in his own field, the cellular genetics of bacteria and their viruses, and engagement with history and philosophy of science. The discovery of bacterial “sex” enabled microbial genetics but, ironically, led Jacob to a sexless concept of reproduction. This approach molded a history that reached across the living world but slighted sex and the complexities of reproduction in multicellular organisms. Readers can learn from its strength and limitations. (shrink)

This paper considers the foundational role of the contagium vivum fluidum—first proposed by the Dutch microbiologist Martinus Beijerinck in 1898—in the history of virology, particularly in shaping the modern virus concept, defined in the 1950s. Investigating the cause of mosaic disease of tobacco, previously shown to be an invisible and filterable entity, Beijerinck concluded that it was neither particulate like the bacteria implicated in certain infectious diseases, nor soluble like the toxins and enzymes responsible for symptoms in others. He offered (...) a completely new explanation, proposing that the agent was a “living infectious fluid” whose reproduction was intimately linked to that of its host cell. Difficult to test at the time, the contagium vivum fluidum languished in obscurity for more than three decades. Subsequent advances in technologies prompted virus researchers of the 1930s and 1940s—the first to separate themselves from bacteriologists—to revive the idea. They found in it both the seeds for their emerging virus concept and a way to bring hitherto opposing thought styles about the nature of viruses and life together in consensus. Thus, they resurrected Beijerinck as the founding father, and contagium vivum fluidum as the core concept of their discipline. (shrink)

This article shows how Lamarckism was essential in the birth of the French school of molecular biology. We argue that the concept of inheritance of acquired characters positively shaped debates surrounding bacteriophagy and lysogeny in the Pasteurian tradition during the interwar period. During this period the typical Lamarckian account of heredity treated it as the continuation of protoplasmic physiology in daughter cells. Félix d’Hérelle applied this conception to argue that there was only one species of bacteriophage and Jules Bordet applied (...) it to develop an account of bacteriophagy as a transmissible form of autolysis and to analyze the new phenomenon of lysogeny. In a long-standing controversy with Bordet, Eugène Wollman deployed a more morphological understanding of the inheritance of acquired characters, yielding a particulate, but still Lamarckian, account of lysogeny. We then turn to André Lwoff who, with several colleagues, completed Wollman’s research program from 1949 to 1953. We examine how he gradually set aside the Lamarckian background, finally removing inheritance of acquired characters from the resulting account of bacteriophagy and lysogeny. In the conclusion, we emphasize the complex dual role of Lamarckism as it moved from an assumed explanatory framework to a challenge that the nascent molecular biology had to overcome. (shrink)