Detection of androgen receptor mRNA in testicular gonocytes at 15.5 dpc. mRNA expression of androgen receptor, Oct-4, AMH, P75, and 3β-HSD was examined by RT-PCR analysis in whole testicular tissue (T) and in magnetic-activated cell sorting isolated gonocytes (G). Results shown are representative of two independent experiments. −RT, control for genomic DNA contamination using Oct-4 primers on isolated gonocytes mRNA extracts.