Figure 7.

Testicular vitamin A homeostasis and germ cell differentiation is affected by the Stra6 genotype. A–F) Immunohistochemistry on frozen sections of testes from Het mice stained with secondary antibody only (A–C) or a STRA6 and secondary antibody together (green; D–F). Sections were counterstained with DAPI (blue). White arrowheads indicate STRA6 protein expression in Sertoli cells of heterozygous mice. G) HPLC measurement of ROL and REs in lipophilic extracts of testes from Het and KO mice raised on VAS or VAD diets. H) Quantitative RT-PCR expression analysis of stimulated by retinoic acid genes in testes normalized to the Gapdh housekeeping gene. I) Quantitative RT-PCR analysis of expression of spermatogenesis marker genes in testes normalized to the housekeeping gene Gapdh. Letters shared between groups indicate no significant difference. Statistical significance was tested by applying a Student’s t test to each group compared with each other group. Data present values from n = 6 per genotype and dietary condition. AT-RAL, all-trans-retinal; c-KIT, tyrosine-protein kinase KIT; ID4, inhibitor of DNA binding 4; SOHLH1, spermatogenesis and oogenesis–specific basic helix-loop-helix 1; WT, wild-type. Original magnification, ×20.