Canadian Health&Care; Mall

Following 8 days of culture in vitro, the developmental distribution of follicles in cortical explants changed significantly (P < 0.05). In untreated cultured explants, the primordial follicle population decreased to comprise only 25.2% 6 2.7% of all of the follicles present, and the percentages of early primary, primary, and preantral follicles increased significantly (P < 0.05) to 58.1% 6 1.4%, 11.6% 6 1.4%, and 5.2% 6 0.8%, respectively (Fig. 6). These data indicate that a large proportion of rabbit primordial follicles spontaneously activate and develop in vitro. The effect of exogenous KITL on follicle recruitment was investigated by treating explants with 50 ng/ml and 150 ng/ml recombinant mouse KITL. Neither dose of recombinant mouse KITL induced a detectable effect on the distribution of follicles in the resting or growing pools compared with untreated cultured explants (Fig. 6). Therefore, recombinant mouse KITL did not promote the activation of primordial follicles in rabbit ovarian cortical explants. Similarly, treatment of rabbit ovarian explants with 150 ng/ml recombinant rabbit KITL did not promote the activation of primordial follicles (see Supplemental Fig. 2).