Relationship between increased heterochromatin region of chromosome 9 and male infertility

Abstract

Infertility is defined when the sexually active couple does not reach a spontaneous pregnancy after a year of exposure to unprotected intercourse. The causes of infertility may be female, male or in both components of the couple. Due to the increasing search for medical assistance for the identification of fertility problems many couples undergo cytogenetic examinations for the evaluation of chromosomal alterations. Many men undergoing tests to detect causes of infertility have often been diagnosed with an increase in the heterochromatin region on chromosome 9. However, this evidence has not been investigated to clarify whether this increase in heterochromatin may be a determining factor in diagnosed male infertility. The formation of heterochromatin is highly regulated by epigenetic events, which in turn can be influenced by the chemical, physical and biological agents to which the organism is exposed in the course of its life. The aim of the present study will be to relate the life habits of men with or without disturbances in daily sperm production (oligozoospermic), the increase of heterochromatic regions in chromosome 9 in this population as well as the gene expression profiles of some genes related to sexual determination, located in both heterochromatic and non-heterochromatic regions of chromosome 9. The identification of the sperm quality will be performed by the spermogram. The characterization of the increase of the heterochromatin region of chromosome 9 will be performed by karyotype analysis obtained from leukocyte culture. Analysis of gene expression will be performed by RT-PCR and of the genes of interest are: (a) Aep1; (B) Vcp; (C) Dmrt1; (D) Hsd17b3; (E) Nr5a1. In addition, a complementary analysis will also be carried out to verify the formation of the acrosome by immunofluorescence detection of VCP protein as well as by the classical PAS cytochemistry technique. (AU)