Comparison of relative expression of AMH ESR1 CCND1 and CDH2 mRNAs in male embryonic gonads during embryogenesis and testes from male chickens. Relative changes in expression of [A] AMH, [B] ESR1, [C] CCND1 and [D] CDH2 mRNAs were determined using quantitative RT-PCR. The asterisks denote statistically significant differences (***P < 0.001, **P < 0.01 and *P < 0.05). Legend: E embryonic day. See Methods for a complete description of the methods.