Figure 1.
Deletion of RB in mutant testes occurs specifically in Sertoli cells. A, PCR amplification of DNA extracted from whole testis of Rbflox/− mice of 4, 6, and 8 wk of age. Primers flanking the loxP sites amplify the recombined Rb conditional allele producing a 260-bp product. B, Quantitative RT-PCR of RNA extracted from isolated Sertoli cells of 6-wk-old animals. Primers were designed flanking the exon 19–20 boundary to show recombination of the Rb conditional allele (**, P < 0.01; control, n = 6; Rb cKO, n = 5). Immunohistochemical staining of RB in 6-wk-old control (C) vs. Rb cKO (D) testis in which Rb staining is ablated in Sertoli cells (Sc) but persistent in spermatogonia (Sg). RQ, Relative quantification.