CCER1 is a germline-specific and intrinsically disordered protein (IDP), mediates postmeiotic spermatid differentiation. Since methylation levels of gene CpG islands (CGIs) often correlate with their tissue-specific expression 13,and Ccer1 appears to be testis-specific; therefore, we investigated that the CGI methylation level of Ccer1 in the testes using bisulfite DNA sequencing.TA Cloning and Sanger Sequencing were performed after bisulfite conversion.