Question

Why is X chromosome inactivation important?

Answer 1

X chromosome inactivation prevents females from having twice as many gene products as males, who only have a single copy of the X chromosome.

Explanation:

The inactivated X chromosome condenses into a compact structure called as Barr body.

Unlike the gene poor Y chromosome , the X chromosome contains over 1000 genes, that are essential for proper development and cell viability. Females carry two copies of X chromosomes, resulting in a double dose of X linked genes. To correct this imbalance , mammalian females have evolved the unique mechanism of X chromosome inactivation.

This is a random process occurring in embryonic stage , as parts of somatic tissue inactivate the maternal X chromosome and other parts inactivate the paternal X chromosome.

Thus transcriptionally silent Barr bodies maintain gene equality between males ( XY )and females ( XX ) .