Wolfram - 29-12-2004 at 07:42
I have a question about the so called Barr body in females. X-linked recessive deseases are very uncommon in females. So how could one of the X-es be
said to be constitute the "inactivate" Barr body. If one X was really inactive there would be no advantage for females to have two X-es
instead of one when considering diseases like hemophilia etc. So how could one of the X be considered inactive, and yet contribute to production of
functional proteins???
Blind Angel - 29-12-2004 at 09:11
Are you talking over recessive genetic illness? Hemophilia and Daltonism are recessive, as long as one of the X has the good gene it'll take over
the damaged one. This is why woman with hemophilia/daltonism are harder to find, then need the two gene to be affected, men only need one since there
are no equivalent on the Y gene.
Hope this help you if i understood well.
Wolfram - 29-12-2004 at 13:38
Well I have found the info myself. I was talking about the "Barr body". It turns out that womens are actually a mosaic of diffrent
X-chromosomes active in diffrent cells, a fact that I was not aware of:
http://en.wikipedia.org/wiki/Barr_body
This means that monozygotic female twin are more phenotypicly diffrent from each other than male monozygotic twins since female monozygotes differ in
the pattern of X-inactivation.
[Edited on 29-12-2004 by Wolfram]
[Edited on 29-12-2004 by Wolfram]