To win the race to fertilize an egg, some sperm cells do not play fair, and actually poison their antagonism, a study has shown.
Experts in Germany found, in a study of mice, that sperm carrying a genetic factor called the ‘T-haplotype’ are able to move rapidly toward their targets.
Meanwhile, their competition without this group of genes is less effective in progress, and is more likely to end up aimlessly in circles.
The researchers added differences in mobility (the ability to move) to a protein called RAC1, which transfers signals from outside of sperm cells to the inside.
In white blood cells and cancer cells, Rac1 is known to play a role in directing its host cells to others that are exiting chemical signals.
Given this, and the findings of the new study, it is possible that the protein plays a similar role in sperm cells, enabling them to find their way to their egg targets.
The findings may also shed new light on the reasons behind some forms of male infertility, increasing the likelihood of future treatments.
To win the race to fertilize an egg, some sperm cells do not play fair – and actually poison their antagonism, a study has shown. Picture: A chalk sketch of sperm swimming (stock image)
What is infertility
Infertility occurs when a couple cannot become pregnant despite having unprotected sex regularly.
It affects one in seven couples in the UK – around 3.5 million people.
About 84 percent of couples will conceive within a year if they have unprotected sex every two or three days.
Some will conceive early, and others later – people should visit their GP if they are concerned about their fertility.
Some treatments for infertility include medical treatment, surgery or assisted conception, including IVF.
Infertility can affect men and women, and risk factors include age, obesity, smoking, alcohol, some sexually transmitted infections, and stress.
Fertility in both sexes decreases with age – the fastest in their 30s.
Paper writer Bernhard Herrmann is the director of the Max Planck Institute for Molecular Genetics in Berlin. ‘
‘The trick is that the t-haplotype “poisons” all sperm, but at the same time produces an antidote, which acts only in the t-sperm and protects them.’
‘Imagine a marathon in which all the participants were poisoned in drinking water, but some runners also take the antidote.’
The team reported that the T-halotype has certain gene variants that are delivered to all sperm and disordered regulatory signals, such as, on their own, inhibiting the so-called ‘progressive’ moment.
However, half the sperm – even those that end up with the T-haplotype when the animal’s chromosomes are evenly divided between them – are able to produce another factor that counteracts this signal disruption, leading them to Allows swimming directly.
In their study, researchers first observed sperm from male mice that had a T-haplotype on only one of their two ‘chromosome 17’, and they found that some cells (with the T-haplotype) were able to swim directly. Were, while others were not.
Upon treating all sperms with a substance that inhibits Rac1, the team noted that cells without the T-haplotype achieved the ability to swim properly.
This, he explained, confirms that the T-helotype interferes with Rac1 activity, which in turn inhibits progressive movement.
Experts in Germany found that in studies of mice, sperm carrying a genetic factor called the ‘T-haplotype’ (picture, below) are able to move rapidly toward their targets. Meanwhile, their competition is less effective without this group of genes (picture, top) – and is more likely to end aimlessly in circles.
In fact, researchers said, any abnormal level of Rac1 activity is bad for sperm. Mice with two copies of the T-haplotype, for example, with one of each of their chromosomes 17, have high levels of Rac1 and are unable to walk.
On the other hand, sperm from mice that do not have the T-haplotype also lose their ability to swim properly when given the Rac1 inhibitor – indicating that low Rac1 levels are also impaired for male fertility.
“The competitiveness of individual sperm depends on an optimal level of active Rac1,” said paper author and molecular geneticist Alexandra Amaral.
“Both a decrease or excessive decrease in Rac1 activity interferes with effective forward movement,” he said.
Aberrant RAC1 activity, the team may speculate, is also responsible for some forms of male fertility in humans – meaning that findings may pave the way toward new forms of fertility treatment.
Professor Herrmann said, “Our data highlight the fact that sperm cells are ruthless competitors,” adding that the T-halotype also demonstrates how some genes use ‘dirty tricks’ to make them pass. Can.
‘Genetic difference may give individual sperm an advantage in the race for life, thus promoting transmission of particular gene variants to the next generation.’
The full findings of the study were published in the journal PLOS Genetics.
How to proceed
Sperm are important in human reproduction and mobility of male cells is important.
To help the sperm cells to move, they developed a ‘tail’, called the flagellum.
The sperm’s tail plays an important role in its ability to swim and results in fertilization of an egg.
Sperm are important in human reproduction and mobility of male cells is important. The sperm’s tail plays an important role in its ability to swim and results in fertilization of an egg.
The sperm tail consists of about 1,000 building blocks, consisting of structures called tubulin, which form long tubes.
In these tubes there are molecules called motorproteins attached.
These pull and twist the sperm tail, enabling them to swim.
The motion of the tail is driven by a mitochondria, the powerhouse of a cell, which produces energy.