THE REAL DIFFERENCE BETWEEN MEN ANDWOMEN

Researchers find 6,500 genes
 differ between the sexes

By Cécile Borkhataria Source

Cécile Borkhataria is an energetic and highly driven multimedia science journalist. She holds a master's degree from Columbia Journalism School, and a Bachelors degree in Biology with Management from Imperial College London. She has worked as a research assistant at CNN New York's medical unit and is currently a reporter for the DailyMail.com. She has worked at Terrapinn Digital in London, where she managed and wrote breaking news and feature content for two websites pertaining to the pharmaceutical industry, 'Vaccine Nation' and 'Total Orphan Drugs.' She has the ability to collaborate and work in a focused and effective manner with a diverse range of people. Although she has a wide range of interests, her primary focus is on scientific, environmental and healthcare reporting. She has been exposed to a multitude of European & International cultures and has completed the International Baccalaureate Diploma at the International School of Luxembourg, which she attended after obtaining a scholarship from a nationwide competition for a fully payed scholarship.   Cécile spent three months in Cambridge, UK, as part of a training placement for her job at the Mail Online in New York. She wrote and reported on stories in Cambridge, and also broadcast and presented many Facebook Live videos for the Cambridge News Facebook page. Highlights include interviewing the lead actors of the ITV and PBS broadcast drama, Grantchester, and covering the launch of Cambridge University's Leverhulme Center for the Future of Intelligence, attended by Professor Stephen Hawking. "  Cécile has covered science and health issues for specialized science, environment and healthcare reporting classes during the Columbia Journalism School 2015-2016 Master's program

“A man does what he can; a woman does what a man cannot.” [Isabel Allende, Chilean-American novelist]

• Researchers analyzed the genetic differences between men and women 
• They analyzed the expression of 20,000 genes in the body tissues of donors
• They found that 6,500 of them are expressed differently in men and women
• For example, gene expression for muscle building was higher in men, and that for fat storage higher in women
• A gene that was active in women's brains may protect the neuron's from Parkinson's disease - which has a higher prevalence and earlier onset in men
• The study emphasizes the need for a better understanding of the differences between men and women in genes that cause disease or respond to treatments.  

Researchers have revealed a breakthrough is how the sexes really differ from each other.
A groundbreaking genetic study pinponted 6500 genes that differ between men and women.
Experts say it could have a profound effect in the way we identify and treat everything from disease to fertility.

Another notable pattern in the findings was a gene that was active in women's brains. The researchers think it may protect the neuron's from Parkinson's disease - which has a higher prevalence and earlier onset in men

WHAT THEY FOUND

Researchers analyzed 20,000 different genes, sorting them by sex and for differences in expression in each body tissue. They found that around 6,500 of these genes were expressed more in one sex, in at least one body tissue. For example, they found that genes that were highly expressed in the skin of men compared to women were related to body hair growth. Gene expression for muscle building was higher in men, and that for fat storage higher in women. The researchers also found sex-linked genes in the mammary glands, half of which were expressed in men. Because men have fully fitted but nonfunctional 'mammary equipment,' the researchers thought that some of the genes might work to suppress lactation. Another notable pattern was a gene that was active in women's brains, and the researchers think it may protect the neuron's from Parkinson's disease - which has a higher prevalence and earlier onset in men.

For example, it found men are more prone to Parkinson's disease, which causes slow movement and loss of balance.
In the new study to learn more about these difference, researchers analyzed 20,000 genes and found that 6,500 of them are expressed differently in men and women in at least one of the body's tissues. 

The roots of the project began several years ago, when researchers Professor Shmuel Pietrokovski and Dr Moran Gershoni of the Weizmann Institute's Molecular Genetics Department wondered why the prevalence of certain human diseases is common. 

Specifically, the focused on the fact that 15 per cent of couples trying to have a baby are infertile, which suggested that genetic mutations that impair fertility are widespread. 

This was perplexing to the researchers, because common sense says that these mutations, which affect the survival of the species by reducing the number of offspring, should have been eliminated by natural selection - a key mechanism of evolution that changes the traits that are inherited by a population via random genetic mutations.
The researchers found that mutations in genes specific to sperm formation persist because these genes are only expressed in men - so a mutation that's only problematic for half the population, no matter how detrimental it is, will be passed on to the next generation by the other half.
But in a new study, published in the journal BMC Biology, the researchers expanded their analyses to include genes that, though are not necessary for fertility, are still expressed differently in men and women.
To identify these genes, the researchers relied on the GTEx project - a large study which recorded human gene expression for many organs and tissues in the bodies of about 550 adult donors.
The researchers analyzed 20,000 different genes, sorting them by sex and for differences in expression in each body tissue.
They found that around 6,500 of these genes were expressed more in one sex, in at least one body tissue.
For example, they found that genes that were highly expressed in the skin of men compared to women were related to body hair growth.
Gene expression for muscle building was higher in men, and that for fat storage higher in women.
They also looked at the tendency for each sex to accumulate mutations to see if natural selection put more or less pressure on genes that are specific to men or women.
In other words, they were trying to found out to what extent harmful mutations are weeded or tolerated.
They found that the efficiency of natural selection is weaker in many such genes.
'The more a gene was specific to one sex, the less selection we saw on the gene,' said Dr Gershoni.
'And one more difference: This selection was even weaker with men.'

Gene expression for muscle building was higher in men, and that for fat storage higher in women. The researchers also found that if a genetic mutation was more specific to one sex, the more it was tolerated and remained in the population

This means that if a genetic mutation was more specific to one sex, the more it was tolerated and remained in the population. While the researchers don't have a complete explanation for why this happens, they suggested that it could be explained by a sexual evolution theory from the 1930s.
'In many species, females can produce only a limited number of offspring while males can, theoretically, father many more; so the species’ survival will depend on more viable females in the population than males,' said Professor Pietrokovski.
'Thus natural selection can be more "lax" with the genes that are only harmful to males.'
The researchers also found other genetic difference in their study.
For example, they found sex-linked genes in the mammary glands, half of which were expressed in men.
Because men have fully fitted but nonfunctional 'mammary equipment,' the researchers thought that some of the genes might work to suppress lactation.

Natural selection - a key mechanism of evo

lution that changes the traits that are inheri-

ted by a population via random genetic mu-

tations. The theory was first put forward by

Charles Darwin (pictured) and Alfred Russ-

el Wallace in a joint presentation in 1858,

which was elaborated in Darwin's famous

1859 book 'On the Origin of Species by Me-

 ans of Natural Selection'  

Other findings were unclear - for example, there were genes that were found to be expressed only in the left ventricle of the heart in women.
But one of these genes, also related to calcium uptake, showed high levels of expression in younger women, and sharply decreased with age.
The researchers think this gene is active until menopause, protecting women's hearts, and eventually leading to heart disease and osteoporosis when its expression is shut down.
Another notable pattern was a gene that was active in women's brains, and the researchers think it may protect the neuron's from Parkinson's disease - which has a higher prevalence and earlier onset in men.
They also identified gene expression in the liver in women that regulated srug metabolism, providing evidence for the known difference in drug processing between women and men.
'The basic genome is nearly the same in all of us, but it is utilized differently across the body and among individuals,' said Dr Gershoni.
'Thus, when it comes to the differences between the sexes, we see that evolution often works on the level of gene expression.'
Professor Pietrokovski added, saying: 'Paradoxically, sex-linked genes are those in which harmful mutations are more likely to be passed down, including those that impair fertility.
'From this vantage point, men and women undergo different selection pressures and, at least to some extent, human evolution should be viewed as co-evolution.
'But the study also emphasizes the need for a better understanding of the differences between men and women in the genes that cause disease or respond to treatments.'