Aim:To investigate the methylation status of the deleted in azoospermia 1(DAZ1)gene promoter region in differentcell types.Methods:Using CpG island Searcher software,a CpG island was found in the promoter region of theDAZ1 gene.The methylation status of this region was analyzed in sperm and leukocytes by bisulfited sequencing.Results:The methylation status of the CpG island in the DAZ1 gene promoter region differed in leukocytes andsperm:it was methylated in leukocytes,but unmethylated in sperm.Conclusion:A differentially methylated region ofthe DAZ1 gene exists in spermatic and somatic cells,suggesting that methylation of this region may regulate DAZ1gene expression in different tissues.(Asian J Androl 2006 Jan;8:61-67)