Page URL:

Every sperm is special, genome sequencing shows

23 July 2012
Appeared in BioNews 666

Results of the first study to sequence the genomes of individual sperm cells obtained from one person have revealed significant genetic differences between them, confirming the belief that each sperm is unique. It is hoped the technique could be applied in fertility treatments to identify genetic mutations that may occur in the recombination process.

'For the first time we were able to generate an individual recombination map and mutation rate for each of several sperm from one person', said Professor Barry Behr from Stanford University in California, USA, who was involved in the study. 'Now we can look at a particular individual, make some calls about what they would likely contribute genetically to an embryo, and perhaps even diagnose or detect potential problems'.

The team overcame significant technical obstacles to sequence each individual sperm cell, and by using a novel technique the researchers managed to separate 91 sperm cells and amplify their DNA for sequencing.

The results showed that recombination - a naturally occurring process whereby chromosomes in the sperm are shuffled around during meiosis - was observed in unexpected places, suggesting this shuffling process is unique in each cell. The findings could explain why siblings have significant genetic differences between them, confirming the recombination process as being partly responsible for genetic diversity.

Whereas previous studies have only looked at recombination across populations, this was the first study to observe the process in individuals. The team now hopes its findings can be applied to fertility  treatments, with some commentators saying the technique could also be used to study cancer.

Study leader Stephen Quake, professor of bioengineering at Stanford University, said: 'People have difficulty conceiving children due to reproductive disorders, and this will provide a very effective way to analyse when there are problems with their sperm'.

Jianbin Wang, a member of Professor Quake's team, explained the technique could also be used to select eggs for IVF. 'We can use those cells to analyse an egg's genome, and screen for genetic diseases', he said. This would be an improvement on existing, more difficult techniques, explained the New Scientist. 'Our technique may make the process easier', said Wang.

The research was published in the journal Cell.

8 June 2020 - by Charlott Repschlager 
Researchers have uncovered important information about genetic crossovers during sperm and egg cell formation that can influence fertility...
28 May 2012 - by Dr Rosie Morley 
A non-hormonal male contraceptive pill could be developed by blocking a newly identified gene involved in the final stages of sperm production, according to scientists...
15 May 2012 - by Dr Victoria Burchell 
In sex education videos the race of sperm to the egg is portrayed like an Olympic swimming final as sperm surge purposefully down the female reproductive tract to the finish line. The reality, however, may be rather less elegant...
9 January 2012 - by Sarah Pritchard 
Researchers have successfully extracted germ cells - the cells that give rise to gametes - from the testes of mice, and used them to grow sperm in the lab...
4 October 2010 - by Owen Clark 
A study has shown that mutations in the NR5A1 gene may be responsible for many unexplained cases of male infertility....
Log in 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.