Why Females Are Stripey
Each of us is made of a mixed-up jumble of cells. Most of you is you, but a few of your cells actually belong to your mom, stowaways that she left in your body.
But thanks to our sex chromosomes, it’s females who are the real mosaics. In this video from Veritasium, you’ll learn how biological females are like calico cats. Early in a female’s life, way back when her embryonic body was little more than a ball of cells just beginning to fold into basic patterns, a molecular coin was flipped inside each of her nuclei, and one of the two X chromosomes was silenced forever.
Why is this? Although our sex chromosomes are tiny compared to the other 44, they contain vital genes. But just like a genetic knockout can cause problems, so can too much of a gene product. Each cell in a female nucleus only expresses the genes on one of the two X chromosomes, muting the other so that the "dose" of X genes is pretty much the same between XY and XX individuals.
Heads or tails, that epigenetic pattern persists for life, and although we can’t see them … women have “stripes”!
Bonus: Features the wonderful molecular animations of Drew Berry!