Figure 1.

Expression of RAR and RXR Variants in both SSC and Progenitor Spermatogonial Populations

(A and B) Representative images of Western blot analyses for RARα, RARγ, RXRα, and RXRβ in ID4-eGFP+ and ID4-eGFP– populations in primary cultures of spermatogonia established from P6–8 pup or adult mice (A) and ID4-eGFP+ spermatogonia isolated directly from the testes of pups (B). Tubulin (TUBB1) loading controls are included beneath each image.

(C) Representative images of immunostaining for expression of RARα, RARγ, RXRα, and RXRβ by ID4-eGFP+ and ID4-eGFP– spermatogonia in cross-sections of testes from pups and adult mice. Arrows and arrowheads indicate ID4-eGFP+ or ID4-eGFP– spermatogonia co-expressing RARα, RARγ, RXRα, or RXRβ, respectively. Boxed regions are magnified in images to the right. Negative controls are presented in Figure S2.