Barr Bodies and Xic

[Procon1234]

Okay, barr bodies had given me headaches . When I read the wiki article about barr bodies, it just gives me lots of questions. Here it is.

1. It is said that all of the somatic cells only have one working chromosome and one barr body. And it is also stated that Xic happens during 2/4 celled embryos. How did the gametes return into it's original state (two working X chromosomes).

2. If the zygote of a female is heterozygous for a recessive X-Linked disease, will she show the symptoms or not (since the cells are mosaic).

3. In Turner's Syndrome, the cells are pretty much the same except that the cells lack barr bodies. What are the roles of the Barr Body in such a way that when a cell doesn't have it, it would be fatal.

Thanks!

[Procon1234]

Ah it seems that further research gave me the answers.

1. The Xist RNA breaks up, reactivating the genes
2. Yes if the recessive cells are higher in amount than the dominant cells
3. It lacks a copt of pseudoautosomal genes