Figure 4.

Ovulation is impaired in IR-cKO mice. Mice were superovulated and sacrificed at 24 h post-hCG when ovulation should be completed and well-formed CL present. (A) IHC of the luteal marker HSD17B7 confirms a trapped oocyte (arrow) residing in CL tissue and not the granulosa cell layer of large follicles. (B) qPCR showing essential ovulation genes are downregulated in total ovarian mRNA from insulin receptor knockout mice [n=10 (control and IR-cKO) and n=5 (Insr-cKO and Igf1r-cKO)] at 24 h post-hCG. Data is presented as mean ± SEM fold expression compared to control which was arbitrarily set to 1. Letters denote means that are significantly different P <0.05. (C) To assess the temporal expression pattern of these markers, five additional females per genotype were superovulated and sacrificed at 8 h, 12 h, and 24 h post-hCG. Relative mRNA expression is presented as mean ± SEM. qPCR of five independent control and IR-cKO females was normalized to control 8 h post-hCG, which was arbitrarily set to baseline of 1 (* P < 0.05, ** P < 0.01, ** P < 0.001 vs. Control).