Epg5 knockout female mice are subfertile. (a) Immunoblotting of ovary samples for the EPG5 protein and ACTB (internal control). (b) Images of ovaries from control and epg5 knockout mice at 8 weeks. Scale bars: 2 mm. (c) The ovary-to-body weight ratio of the control and epg5 knockout mice. (d) Subfertility of female epg5 knockout mice. Both control (n = 5) and epg5 knockout (n = 5) females were mated with WT male mice; continuous breeding showed the cumulative number of progeny per female mouse. The asterisks indicate statistically significant differences. (e) the average litter size of control (n = 5) and epg5 knockout (n = 5) females. (f) Representative histology of ovaries sections from 16-week-old epg5 knockout females stained with hematoxylin and eosin. (g) Numbers of follicles at different stages in ovary sections from 16-week-old control and epg5 knockout mice (n = 4 for each group). Follicles were counted; black arrowheads in F point to follicles at different stages. PmF, primordial follicle; PF, primary follicle; SF, secondary follicle; AF, antral follicle. CL: Corpus luteum. Scale bars: 100 µm. Data are expressed as the mean ± S.E.M. *P < 0.05, **P < 0.01. ***P < 0.001.