Format

Send to

Choose Destination
Hum Mol Genet. 2014 Jan 1;23(1):12-23. doi: 10.1093/hmg/ddt392. Epub 2013 Aug 13.

Epigenetic regulation of the RHOX homeobox gene cluster and its association with human male infertility.

Author information

1
School of Medicine, Department of Reproductive Medicine, University of California, San Diego, 9500 Gilman Drive, MC 0695, La Jolla, CA 92093-0864, USA.

Abstract

The X-linked RHOX cluster encodes a set of homeobox genes that are selectively expressed in the reproductive tract. Members of the RHOX cluster regulate target genes important for spermatogenesis promote male fertility in mice. Studies show that demethylating agents strongly upregulate the expression of mouse Rhox genes, suggesting that they are regulated by DNA methylation. However, whether this extends to human RHOX genes, whether DNA methylation directly regulates RHOX gene transcription and how this relates to human male infertility are unknown. To address these issues, we first defined the promoter regions of human RHOX genes and performed gain- and loss-of-function experiments to determine whether human RHOX gene transcription is regulated by DNA methylation. Our results indicated that DNA methylation is necessary and sufficient to silence human RHOX gene expression. To determine whether RHOX cluster methylation associates with male infertility, we evaluated the methylation status of RHOX genes in sperm from a large cohort of infertility patients. Linear regression analysis revealed a strong association between RHOX gene cluster hypermethylation and three independent types of semen abnormalities. Hypermethylation was restricted specifically to the RHOX cluster; we did not observe it in genes immediately adjacent to it on the X chromosome. Our results strongly suggest that human RHOX homeobox genes are under an epigenetic control mechanism that is aberrantly regulated in infertility patients. We propose that hypermethylation of the RHOX gene cluster serves as a marker for idiopathic infertility and that it is a candidate to exert a causal role in male infertility.

PMID:
23943794
PMCID:
PMC3857941
DOI:
10.1093/hmg/ddt392
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center