X Chromosome: Inactivation
Janice Y Ahn and JT Lee
Alrighty guys, I’m going to tell you a story about X-Chromosomes. So just sit tight as I go on about biology. X-Chromosome Inactivation (also known as XCI) occurs in all female mammals as a mechanism that ensures survival. How? Well, remember, the X chromosome contains countless genes, many more than the Y chromosome, so if both chromosomes were to work, then the body would be making twice the amount of proteins (other things will happen, but I want to ignore that for now). By making twice the amount of proteins as normal, there would be a sex difference between proteins made and thereby impairing the development between the genders. So, a mechanism was developed to help prevent that, otherwise known as X-Chromosome Inactivation. A random X chromosome of the pair is deactivated and condenses to become a Barr body. The Barr body is pretty much just left alone and you can generally find it chilling in the placenta cells of most female mammals (with specie exceptions of course).
So, besides just knowing that female mammals have this mechanism, why else do we need to learn about it? WELL, knowing about X-Chromosome Inactivation can also help us understand many other biological, chromosomal disorders and abnormalities. Abnormalities such as the Triple X, Klinefelter Syndrome, and Turner Syndrome can use the X-Chromosome Inactivation mechanism to better understand this (granted, it is only one of multiple other devices that can affect these syndromes).
Also, X-Chromosome Inactivation can help to understand genetic mutations and how some mutations can occur and thereby help to understand how recessive traits work.
I dunno guys, I just felt like you all needed to know this if you didn’t already. This is still one of the best thing I’ve ever learned ever and pretty much helped to to understand a lot of evolutionary theories in a more practical sense. Also disclaimer; I’m not a biologist, so if anything I said is incorrect, please feel free to message me and correct me. Please and thanks.