[Epigenetic mechanism of obesity-induced male infertility]

Epigenetic changes induced by obesity can lead to male infertility phenotype. As for the relationship between obesity and male infertility, early studies mostly focused on the endocrine aspect. Recent studies have found that obesity can cause epigenetic changes, such as DNA methylation, residual histone modification, small RNA, etc, affecting sperm maturation and development. DNA methylation is a regulatory marker on cytosine residue of cytosine-phosphate-guanine dinucleotide. Obesity leads to abnormal DNA methylation, changes mRNA expression abundance, affects imprinted gene expression induses imprinted gene diseases. The modification methods of residual histones include methylation, acetylation, etc. They can interact or cooperate to ensure the normal growth and development of sperm. Obesity changes methylase and acetylase activities and directly affects methylation and acetylation of residual histones, and the expression of micro-RNAs in sperm as well, consequently causing sperm defects. This article reviews epigenetic changes caused by obesity and the mechanism of male infertility.