DNA Methylation Mediates Sperm Quality via and Regulation in Japanese Flounder ().

DNA methylation is an important way to regulate gene expression in eukaryotes. In order to reveal the role of DNA methylation in the regulation of germ cell-specific gene expression during spermatogenesis of Japanese flounder (), the expression profiles of () and () genes in the gonads of female, male, and sex-reversed pseudo-male were analyzed, and the dynamic of DNA methylation was investigated. As a result, and genes were highly expressed in the testis of both male and pseudo-male , with significant variation among male individuals. The DNA methylation levels in the promoter regions of both and were negatively correlated with their expression levels, which may contribute to the transcriptional regulation of genes during spermatogenesis. There was also sperm quality variation among male , and the sperm curvilinear velocity was positively correlated with the expression of both and genes. These results indicated that the DNA methylation in and promoter regions may affect the initiation of gene transcription, thereby regulating gene expression and further affecting the spermatogenesis process and gamete quality in .