Dosage Compensation
X inactivation plays a key role in dosage compensation mechanisms that allow for equal expression of the X and autosomal chromosomes. Different species have different dosage compensation methods, with all of the methods involving the regulation of an X chromosome from one of the either sexes. Some methods involved in dosage compensation to inactive one of the X chromosomes from one of the sexes are Tsix antisense gene, DNA methylation and DNA acetylation; however, the definite mechanism of X inactivation is still poorly understood. If one of the X chromosomes is not inactivated or is partially expressed, it could lead to over expression of the X chromosome and it could be lethal in some cases.
Turner's Syndrome is one example of where dosage compensation does not equally express the X chromosome, and in females one of the X chromosomes is missing or has abnormalities, which leads to physical abnormalities and also gonadal dysfunction in females due to the one missing or abnormal X chromosome. Turner's syndrome is also referred to as a monosomy X condition.
Read more about this topic: XIST (gene)
Famous quotes containing the word compensation:
“I do not want to be covetous, but I think I speak the minds of many a wife and mother when I say I would willingly work as hard as possible all day and all night, if I might be sure of a small profit, but have worked hard for twenty-five years and have never known what it was to receive a financial compensation and to have what was really my own.”
—Emma Watrous, U.S. inventor. As quoted in Feminine Ingenuity, ch. 8, by Anne L. MacDonald (1992)