Page URL:

Molecular approach to male infertility

31 August 2010
Appeared in BioNews 573

Research carried out at the University of Pennsylvania School of Medicine suggests that the packaging of DNA affects the production of sperm and could explain some cases of male infertility.

The production of sperm and eggs (gametes) involves a specialized form of cell division called meiosis, which is tightly regulated by molecular signals in the cell. In a process referred to as 'epigenetics', the expression of genes can be altered without changing the DNA itself. DNA is wrapped around proteins called histones. By chemically changing the histones, DNA is encouraged to bind more or less tightly: this effects the copying of DNA and gene expression.

It is known that sperm and egg formation is influenced strongly by epigenetic mechanisms and the team, led by Professors Shelley Berger and Jerome Govin, set out to identify the importance of histone modification in fertility. The researchers used yeast as an experimental model and developed a way of systematically mutating histone proteins. They screened all the yeast cells to find mutants that were unable to form spores - a process that is analogous to sperm formation in humans.

Their analysis showed that sites on histone proteins H3 and H4 were important. One critical modification site is threonine-11 on histone H3 (H3T11), the phosphorylation of which is required to complete meiosis. They also found a trio of lysines on histone H4, whose acetylation allows efficient compaction of chromosomal DNA into mature spores.

Given the conservation of gamete formation across evolutionary time, it is likely that these epigenetic markers in yeast are also present and serve similar functions in humans. This study may therefore lead to the identification of potential biomarkers for male infertility.



'It is almost certain that some fertility problems relate to epigenetics,' Professor Govin said.

'We are going to find brand new chromatin regulatory mechanisms that will be conserved all the way from yeast to mouse,' Professor Berger predicted.

Molecular approach could be the key to understanding male infertility
Sify |  26 August 2010
Researchers identify molecular signals that impact male fertility: Research |  25 August 2010
18 September 2017 - by Dr Kimberley Bryon-Dodd 
A type of chemical found in various personal beauty products and plastics may affect sperm and lower reproductive success, according to a new study...
13 June 2011 - by Kyrillos Georgiadis 
A new fertility test for men which can detect DNA damage in sperm has been developed in the UK. The test, called SpermComet, could save couples undergoing fertility treatment both time and money, since it will allow clinics to fast-track patients to the most appropriate treatment, say its developers...
31 May 2011 - by Dr Caroline Hirst 
Researchers from Johns Hopkins University, USA, have found a link between female infertility and genetic variation in a gene regulating cholesterol uptake...
21 March 2011 - by Rosemary Paxman 
Progesterone released from an egg may help guide sperm towards it and assist sperm to penetrate the egg's protective layers, according two studies published in Nature...
9 August 2010 - by Victoria Kay 
A chemical found in some common plastics may be linked to reduced fertility in men, according to a new report. A US study found that men with the highest levels of Bisphenol A (BPA) in their urine had a sperm count 23 per cent lower on average than those with the lowest BPA levels...
7 December 2009 - by Heidi Colleran 
A team of scientists has taken male fertility research a major step forward, with the discovery of how androgenic hormones regulate the production of sperm in the testes of mice. The breakthrough, reported in the journal The Federation of American Societies for Experimental Biology (FASEB), may lead to greater understanding and control of male fertility, including the development of a male contraceptive 'pill', and treatments for infertility....
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.