To whom do sperm and ova belong? Few tissues are produced by the human body with more waste than the germ cells. Yet dominion over the germ cells, and over the early embryo that results from their union in vitro, is behind much of the emotion that modern reproductive intervention can engender. The germ cells differ from other human tissues that can be donated or transplanted because they carry readily utilizable genetic information. Eventual expression of the germ cells' genetic potential (...) is the legitimate concern and responsibility of their donors, although in the right circumstances the responsibility can by agreement be entrusted to institutions administering gamete or embryo donor programmes; these institutions, in turn, may need to assume responsibility for decisions if, in the case of embryo storage, the wishes of the two donors conflict. The fact of sperm and ovum ownership (and the genetic potential that goes with it) before individuals part with these tissues is beyond dispute. Some contentious issues may be clarified if this area of human dominion, namely control over genetic expression among offspring, is acknowledged to be the legitimate persisting concern of those who have produced sperm and ova after storage commences. (shrink)