“There is several times more genetic variety among women than among men.” What drugs are you on?
Reading is my drug of choice.
Women Are Very Much Not Alike, Gene Study Finds
In a study published today in the journal Nature, scientists said they had found an unexpectedly large genetic variation on the X chromosome among women. The findings were published in conjunction with the first comprehensive decoding of the chromosome, which appeared in the same journal.
Females can differ from each other almost as much as they do from males in the behavior of many genes at the heart of sexual identity, researchers said.
“Literally every one of the females we looked at had a different genetic story,” said Duke University genetics expert Huntington Willard, who co-wrote the study. “It is not just a little bit of variation.”
To avoid any toxic effect from double sets of X genes, female cells randomly choose one copy of the X chromosome and silence it – or so scientists had believed.
The new analysis found that the second X chromosome was not a silent partner. As many as 25% of its genes are active, serving as blueprints to make necessary proteins.
To investigate this variation, Carrel and Willard isolated cells from 40 women and measured the activity of hundreds of genes to see whether those on the second X chromosome were active or silent.
Although those extra genes were supposed to be turned off, they found that about 15% of them in all female cells were still active, or in the terminology of genetics, “expressed.” In some women, up to an additional 10% of those X-linked genes showed varying patterns of activity.
“This is 200 to 300 genes that are expressed up to twice as much as in a male or some other females,” Willard said. “This is a huge number.”
Researchers were surprised that they found so many unexpected differences in the behavior of the one sex chromosome that men and women share.
Though there is dramatic variation in the activation of genes on the X chromosomes that women inherit, there is none among those in men, the researchers reported.
Researchers have yet to understand the effect of so many different patterns of gene activation among women or determine what controls them, but all the evidence suggests that they are not random.
“What had looked like a simple yes or no has turned into a thousand shades of gray,” said molecular biologist David Page, an expert on sex evolution at the Whitehead Institute for Biomedical Research in Cambridge, Mass.
Illuminating this complex palette was the work of an international team of 250 scientists led by geneticist Mark Ross at the Wellcome Trust Sanger Institute in Hinxton, England. The team produced the first complete sequence of the X chromosome about two years after the decoding of the male Y chromosome.
The international team identified 1,098 functional genes along the X chromosome, more than 14 times as many as scientists had located on the tiny Y chromosome.
X–1098 genes with no variation in activation
X1–1098 genes with dramatic variation in activation
X2–200-300 genes with dramatic variation in activation
Females are genetically superior to males in every way.
gummygunk
titsay
origamiaround
andulkaphoto
areudirty
stormborns
