Association between sperm MT-COX1 gene variations and semen quality in the Chinese Han population

Abstract Backgroud: Male sperm quality has declined as a whole in the last 30 years and our previous study found that there are many specific variations in male sperm mitochondria, including MT-COX1. In this study we attempted to explore the correlation between human sperm MT-COX1 gene variations and male semen quality in a Chinese Han population. Methods and results: There were 477 male patients from the Second Affiliated Hospital of Zhengzhou University from 2010 to 2021, of whom 331 were retrospective studies and 146 were prospective studies. And 4 oligoasthenoteratospermia samples and 13 normal sperm samples were collected for low-throughput sequencing of the whole human genome. The semen samples were divided into three groups according to the types of genetic variation at the m.6023G>A locus: G/G genotype (wild type), G/A genotype and A/A genotype. The results of a prospective study show that the A/A genotype had higher sperm density and motility than the G allele carrier (G/G+G/A). And DNAAF6 gene variation may be associated with oligoasthenoteratospermia, the upstream of the 107243978 position of DNAAF6 gene variation might have the binding of hsa-miR-4311 to the 3'UTR of DNAAF6 gene. Conclusions: We first found that the MT-COX1 gene of spermatozoa of the Chinese Han population has varied since 2014. Furthermore, the A/A genotype had better sperm quality than the G allele carriers (G/G+G/A), and the 107243978 position variation of the DNAAF6 gene might affect the gene expression by affecting the stability of transcripts.