Female Supremacy Articles - Page 14

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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.