Testicular cell types affected by lack of functional insulin. A: Testes sections from 9-week-old wild-type, Akita heterozygote, and homozygote males. GATA4 staining of Akita homozygous
testes reveals a retained population of Sertoli cells (n = 3). B: qRT-PCR analysis of cell types in control and Akita testes suggests increased Sertoli cell and spermatogonia cell populations
in homozygous Akita testes, while both spermatocytes and spermatids are virtually absent compared with controls and heterozygotes.
Insulin treatment reversed this trend and restored all cell populations in the testes to normal levels. n = 5 for wild-type (WT), Akita heterozygous (het), and Akita homozygous (hom) mice; n = 2 for Akita homozygote + insulin (hom + ins). *P < 0.05, **P < 0.01. (A high-quality digital representation of this figure is available in the online issue.)