X-Inactivation and the Barr Body
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
In each XY-system female cell, one of two X chromosomes is randomly inactivated early in development, condensing into a visible Barr body.
Show
A calico cat's patchwork coat shows two coat-color alleles, each active only where that particular X stayed switched on.
Watch for
Inactivation happens randomly per cell, not uniformly, so a heterozygous female is a mosaic of both alleles, not a blend.
Builds on
Unlocks
- Nothing yet depends on this.