The bovine genome contains three differentially methylated paralogous copies of the P450c17 encoding gene (CYP17A1)

► The bovine genome contains three very similar paralogous copies of the CYP17A1 gene. ► CYP17A1a, CYP17A1b and CYP17A1x are located on bovine chromosome 26. ► CYP17A1a is hypo-methylated and transcribed in P450c17 active tissues. ► CYP17A1b and CYP17A1x are methylated and silent.