X Chromosome’s Silencer

Scientists from the University of Michigan have discovered what actually silences X chromosome in girls. The findings could lead to ways to counter X–linked diseases in women.

It is widely believed that a molecule known as Xist RNA is responsible for silencing X chromosome. However, researchers through their research have shown that Xist is not solely responsible for silencing X chromosome. Nearly, every female carries two X chromosomes in every cell but one of them is usually idle.

Researchers, through their research have established that Xist has accomplices that reside in the X chromosome, which are destined to get silenced. Although there are many genes that are totally idle in the inactive X chromosome, there are a few genes that are active therein. Scientists were concerned with these active genes. Since these active genes are a part of both, the active and inactive X chromosomes, they produce more gene product in females than in males who have only one X chromosome. Scientists believe that it is this higher gene production that triggers X–inactivation selectively in females as compared to males.