The Conservation of the Original X and Dosage Compensation in the Face of X-polysomy
From the variety of X-polysomic conditions described in man in recent years, one remarkable rule emerged: the number of sex chromatin bodies always equals the number of X-chromosomes present minus one. The dosage compensation mechanism which nullifies the genetic disparity between the male and the female also serves to minimize the detrimental consequences of X-polysomy. But when this rule is viewed against the broad background of knowledge of the whole infraclass Eutheria, it becomes just a small portion of the grand scheme of dosage compensation. In this chapter, it will be shown that the dosage compensation mechanism is universal to all the placental mammals in a qualitative as well as a quantitative sense in that the aim is to preserve only one original X in the functional state in each diploid somatic cell under all the normal and abnormal conditions.
KeywordsTurner Syndrome Placental Mammal Dosage Compensation Tritiated Thymidine Gonadal Dysgenesis
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