Fig. 2

Primordial follicle formation and meiotic progression in perinatal mouse ovaries. a Percentage of oocytes in follicles (± SEM) over time. Different letters indicate a significant difference between groups (P < 0.05; n = 4–5 ovaries per time point) as determined by one-way ANOVA followed by Newman-Keuls multiple comparisons test. b Percentage of follicles with oocytes at the pre-diplotene stage out of total follicles (± SEM) in perinatal mouse ovaries. Different letters indicate a significant difference between groups (P < 0.05; n = 4–5 ovaries per time point) as determined by one-way ANOVA followed by Newman-Keuls multiple comparisons test. c-f Representative histological images of perinatal mouse ovaries stained with hematoxylin and eosin. c 17.5 dpc ovary showing pre-diplotene oocytes in germ cell cysts indicated by white arrows. d 17.5 dpc ovary showing a primordial follicle containing a pre-diplotene oocyte indicated by a white arrow. e PND3 ovary showing diplotene oocytes not yet enclosed in primordial follicles indicated by white arrows. f PND5 ovary showing a diplotene oocyte in a primordial follicle indicate by a white arrow. Scale bar = 20 μM