Waye J S, Willard H F
Department of Medical Genetics, University of Toronto, Ontario, Canada.
Nucleic Acids Res. 1987 Sep 25;15(18):7549-69. doi: 10.1093/nar/15.18.7549.
The human alpha satellite DNA family is composed of diverse, tandemly reiterated monomer units of approximately 171 basepairs localized to the centromeric region of each chromosome. These sequences are organized in a highly chromosome-specific manner with many, if not all human chromosomes being characterized by individually distinct alphoid subsets. Here, we compare the nucleotide sequences of 153 monomer units, representing alphoid components of at least 12 different human chromosomes. Based on the analysis of sequence variation at each position within the 171 basepair monomer, we have derived a consensus sequence for the monomer unit of human alpha satellite DNA which we suggest may reflect the monomer sequence from which different chromosomal subsets have evolved. Sequence heterogeneity is evident at each position within the consensus monomer unit and there are no positions of strict nucleotide sequence conservation, although some regions are more variable than others. A substantial proportion of the overall sequence variation may be accounted for by nucleotide changes which are characteristic of monomer components of individual chromosomal subsets or groups of subsets which have a common evolutionary history.
人类α卫星DNA家族由多样的、串联重复的单体单元组成，这些单体单元约171个碱基对，定位于每条染色体的着丝粒区域。这些序列以高度染色体特异性的方式组织，许多（如果不是所有的话）人类染色体都具有各自独特的α卫星亚群特征。在这里，我们比较了153个单体单元的核苷酸序列，这些单体单元代表了至少12条不同人类染色体的α卫星成分。基于对171个碱基对单体中每个位置的序列变异分析，我们推导了人类α卫星DNA单体单元的共有序列，我们认为该序列可能反映了不同染色体亚群从中进化而来的单体序列。在共有单体单元的每个位置，序列异质性都很明显，不存在严格核苷酸序列保守的位置，尽管有些区域比其他区域更具变异性。总体序列变异的很大一部分可能是由核苷酸变化引起的，这些变化是具有共同进化历史的单个染色体亚群或亚群组的单体成分所特有的。
