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人类染色体微小变异的意义还未确定。以前的报导曾注意到,着丝点附近的异染色质(包括高度螺旋化的DNA)和Y染色体远端的微小变异。这种变异也可存在于正常个体中,所以它可能代表构成异染色质的正常多态性。然而,与低等动物不同,异染色质内DNA碱基组成的比例在同一物种是恒定的,这表明构成异染色质的重要作用。而且,对植物和低等动物的研究也说明异染色质的结构改变可产生表现型效应。
The significance of human chromosome minor variations has not been established. It has been previously reported that heterochromatin (including highly helical DNA) near the centromere and small variations distal to the Y chromosome have been noted. This variation can also occur in normal individuals, so it may represent the normal polymorphism that constitutes heterochromatin. However, unlike lower animals, the proportion of DNA base within the heterochromatin is constant in the same species, suggesting an important role for heterochromatin. Moreover, studies on plants and lower animals have also demonstrated that structural changes in heterochromatin can produce phenotypic effects.