剂量补偿机制(Dosage compensation mechanism)是雌性和雄性X染色体表达平衡的关键, 保证两性间由X染色体编码的蛋白质或其他酶类物质在数量上达到平衡。不同生物的剂量补偿机制各不相同, 迄今研究表明剂量补偿机制主要有以下3种模式：通过雄性的单个X染色体表达加倍; 通过雌性的一条X染色体失活; 通过雌性的两个X染色体的表达减半来达到平衡。对剂量补偿的研究有助于揭示X连锁基因的调控机理、性染色体的进化和分化过程, 以及解释性染色体畸变的机理, 因此, 文章将对这种重要的调控机制研究现状及进展进行简要论述。
Dosage compensation mechanism is crucial for the balance expression of X chromosome genes, which ensures the protein or enzyme encoded by the X chromosome to be equal or almost equal expression amounts between males and females. However, different organisms have evolved distinct dosage compensation strategies, and so far three kinds of dosage compensation strategies among organisms have been reported. The first strategy is that the single male X chromosome expression is doubly activated; the second one is to inactivate one female X chromosome by leaving both sexes with one active allele; and the third one is to reduce the expression to half activity in both X chromosomes of the female. The study of dosage compensation will be useful to reveal the mechanism of regulation of X-linked genes as well as the evolution and the differentiation progress of the sex chromosome, and it can also contribute to illustrate mutation and distortion of sex chromosome. Therefore, this paper briefly reviewed and discussed the progresses and prospects of the important mechanism of dosage compensation.
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