Dosage Compensation Mechanism
As human females have two X chromosomes, this means they have the ability to produce twice as much X-linked gene product, this Dosage Compensation Mechanism is responsible for keeping levels of the X-linked gene product similar in both males and females. Therefore, such a mechanism only exists in females. Dosage compensation requires RNA polymerase, Tsix transcript and Xist transcript as well as the X chromosomes of developing embryonic cells. Note that each transcript is transcribed on one chromosome each. Xist acts as to ensure inactivation of X chromosome whereas Tsix ensures X chromosome remains active. Such activity is carried out from the X inactivation centre [1]. This mechanism follows the process of X-inactivation, also termed Lyonization, in which regardless of the amount of X chromosomes are present, all but one are inactivated.
References
- ↑ Lodish, et al. 2008. (Molecular Cell Biology) 6th edition. pg 959 Fig22-7