La physiologie ovarienne : ce que nous disent les souris...

Abstract

La souris, eprouvette vivante, permet d' approcher la fonction du produit des genes par les effets observes apres leur invalidation ou leur surexpression. A chaque etape, de l' organogenese ovarienne a la fecondation de l' ovule, l' activation de certains genes est indispensable. Certains sont d' expression ubiquiste, d' autres sont, a l' inverse, tres specifiques, controlant la constitution du stock de cellules germinales, la croissance et la differenciation du follicule puis l' ovulation... Si le fait que les gonadotrophines hypothalamo-hypophysaires soient indispensables a la croissance du follicule n' a surpris personne, la mise en evidence des roles de la leptine et du facteur hypothalamique Nlh12, entre autres, a permis de preciser les liens entre metabolisme et fertilite.

Generation of transgenic mice that lack functional copies of one or several endogenous genes, or that overexpress an exogenous gene, as well as the phenotypic characterization of spontaneous mutations, has recently allowed physiologists to investigate the functional role of these genes in vivo. In this review, we describe mutations that specifically affect fertility in female mice. Some mutations affect sexual differentiation and organogenesis of the ovaries, basal and terminal follicular growth and atresia, and/or ovulation. Other mutations indirectly alter female fertility by interacting with metabolism. Among all the mutations that have been shown to alter female fertility, some of them were expected (FSHbeta, estradiol receptor), while others were serendipitous (Nhlh2, CSF1). Finally, transgenic technology proves useful to produce animal models of human diseases such a Turner's syndrome or polycystic ovaries. [References: 44]