Figure 1.

Kiss1r haplo-insufficiency induces a progressive loss of ovarian follicles. Quantitative data from morphometric analyses of ovarian follicles, at early stages of folliculogenesis, in WT (Kiss1r^+/+) and heterozygous (Kiss1r^+/−) mice are shown, at 3 (A), 16 (B), and 32 weeks of age (C). Primordial, primary, and secondary preantral follicles were counted in serial 7-μm sections of ovaries from Kiss1r^+/+ and Kiss1r^+/− mice. No differences in the number of follicles at any stage of development were detected between genotypes at week 3, ie, before puberty. By 16 weeks of age, only the number of primary follicles was reduced significantly in Kiss1r^+/− mice, but by 32 weeks of life there was a substantial loss of both primordial and secondary follicles, and a consistent trend for lower number of primary follicles in Kiss1r^+/− mice (n = 4 mice/group). Bars represent means, and vertical bars are ± SEM. *, P < .05.