Research finds that female reproductive tract can remove unwanted sperm after sexual intercourse

About the position. let’s start. let’s go!

In the conception race, most people have been taught that it is the strength and speed of the swaying ejaculation that determines which sperm reach the finish line first.

But science is beginning to learn that various chemicals in the female reproductive system can promote or interfere with the chance of sperm winning.

And it seems to occur early in the race-in Female cervix.

A new study found that sperm swimming movements, velocity, and survival were affected by the level of genetic compatibility between female cervical mucus and male sperm Published Wednesday in Proceedings of Royal Society B Journal..

Previous work by the same author I found the same thing happening in female follicular fluid.

Think of it as a chemical “screening hat” (determined by female reproductive secretions). This helps the sperm most likely to give the offspring a genetic boost.

“It seems that the entire female reproductive tract has evolved to eliminate “unwanted” sperm,” said Yucca Kelainen, associate professor of the Faculty of Environment and Biological Sciences at the University of Eastern Finland, who wrote both studies.

“We argue that the mysterious selection of women can occur in multiple stages while the sperm move from the vagina towards the unfertilized egg,” she says. It was

It’s all about survival

Reproduction in mammals It provides genes that are beneficial to the child’s immune system. Curiously, the most compatible males are those who provide a completely different set of immune defense genes than females.

“The more diverse their genes are, the more diverse the types of infections you can fight for,” said assistant John Fitzpatrick. Professor of Zoology, Stockholm University, Sweden In a prior interview with CNN..

“If your partner has a slightly different combination of these genes from you, you’ll have offspring that can fight a wider array of pathogens and diseases,” he said, but not in the field. Fitzpatrick is involved in a new study that she added.

Previous studies have found that men and women can choose to have sex with each other based on chemical clues about their genetic compatibility. Men can just sniff women who ovulate T-shirt smell, Women seem to prefer the scent of men with different immune defense genes, It could boost the evolutionary ladder to her offspring.

But a new study found that decisions continue to be made by the reproductive process rear The couple mated.

For example, Human sperm surface It contains olfactory receptors that can detect genetically distinct molecules. In women, the eggs appear to leave behind a chemical breadcrumb, act differently on sperm from different men, and virtually choose which sperm will succeed.

Initial selection process

After the vagina (that is Kekäläinen (Not yet studied), the first major obstacle sperm encounter on their journey to fertilization is the cervix of a woman sitting at the entrance to the uterus. The cervix is ​​usually filled with thick mucus. The mucus thins out just before a woman ovulates and is more likely to penetrate.

Mucus is thought to help normal sperm move more easily and prevent abnormal or poorly functioning sperm from continuing into the female genital tract.

But does that also apply to encouraging sperm from environmentally-friendly mate? Kekäläinen and his colleagues tested that conjecture by combining every possible permutation of cervical mucus in nine women with sperm in eight men. Next, the success of sperm swimming was compared to each person’s genotype.

Sure enough, studies found that female cervical mucus affected some men’s sperm more strongly than others. Sperms that are not genetically similar to eggs performed better and had increased fertilization changes.

Infertility research required

The findings may be used to help some couples better understand infertility, and hopefully “promote the development of more personalized infertility diagnoses and improve their accuracy”. Is expected.

Approximately 30% to 40% of couples facing infertility do not know the exact reason for not being able to conceive, so “when both are diagnosed as fertile, they can help understand the reason behind It’s possible, their reproductive problems,” said Kekäläinen.

“Therefore, we will encourage future infertility research and test the possibility that infertility is not always a pathological condition, but instead provides a proven evolutionary mechanism,” she says. Said.

But even if a couple discovers that they are genetically incompatible, like nature, that doesn’t mean they can’t have a completely healthy baby, she added.

“Matchel level incompatibility is likely to reduce the chance of conception, but it may not often prevent it altogether,” Kekarinen said. “Moreover, spouse-level compatibility does not mean that partners are otherwise incompatible in terms of personality.”