Figure 1

Morphological and histological features of ovarian tissues of the wild ground squirrel during the breeding and nonbreeding periods . Marked seasonal differences were observed in ovarian volume (a) and weight (b). Subsequently, HE staining was performed for the ovaries of the breeding season (c) and nonbreeding season (d), and follicles of the two periods were manually quantified accordingly (e and f). g and h were the schematic diagrams for the varied folliculogenesis of the breeding and nonbreeding periods. B, breeding season; NB, nonbreeding season; MF, mature follicle; CL, corpus luteum; SF, secondary follicle. *, P < 0.01.