Clusters of alpha satellite on human chromosome 21 are dispersed far onto the short arm and lack ancient layers.
Clusters of alpha satellite on human chromosome 21 are dispersed far onto the short arm and lack ancient layers.
复制标题
人类 21 号染色体上的 α 卫星簇分散在短臂上，缺乏古老的层。
DOI：
10.1007/s10577-016-9530-z
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Doering,Jeffrey
中科院分区：
文献类型：
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作者：
Ziccardi,William;Zhao,Chongjian;Shepelev,Valery;Uralsky,Lev;Alexandrov,Ivan;Andreeva,Tatyana;Rogaev,Evgeny;Bun,Christopher;Miller,Emily;Putonti,Catherine;Doering,Jeffrey
人类α卫星（AS）序列结构域，目前作为着丝粒的功能通常两侧层的进化较老的AS，推测代表早期灵长类动物着丝粒的残余物。几个人类染色体的研究表明，这些老AS阵列排列在一个年龄梯度，与最古老的阵列最远的功能着丝粒和阵列逐渐接近着丝粒逐渐年轻。AS在人类21号染色体（HC21）上的组织尚未得到很好的表征。我们已经使用了新的HC21序列数据和HC21p YAC地图来确定AS阵列的大小，组织和位置，并将它们与其他染色体上发现的AS阵列进行比较。我们发现，大多数HC21 AS序列存在于染色体的p臂上，并被组织成至少5个不同的孤立的簇，这些簇分布在离功能性着丝粒比通常在其他染色体上看到的AS更大的距离上。使用系统发育和L1元件年龄估计，我们发现，所有的HC21 AS集群外的功能着丝粒是一个类似的相对较近的进化起源。HC 21不包含与其他染色体上存在的早期灵长类进化相关的古老AS层，可能是由于HC 21的p臂和其他近端着丝粒染色体在大约2000万年前经历了实质性重组。
Human alpha satellite (AS) sequence domains that currently function as centromeres are typically flanked by layers of evolutionarily older AS that presumably represent the remnants of earlier primate centromeres. Studies on several human chromosomes reveal that these older AS arrays are arranged in an age gradient, with the oldest arrays farthest from the functional centromere and arrays progressively closer to the centromere being progressively younger. The organization of AS on human chromosome 21 (HC21) has not been well-characterized. We have used newly available HC21 sequence data and an HC21p YAC map to determine the size, organization, and location of the AS arrays, and compared them to AS arrays found on other chromosomes. We find that the majority of the HC21 AS sequences are present on the p-arm of the chromosome and are organized into at least five distinct isolated clusters which are distributed over a larger distance from the functional centromere than that typically seen for AS on other chromosomes. Using both phylogenetic and L1 element age estimations, we found that all of the HC21 AS clusters outside the functional centromere are of a similar relatively recent evolutionary origin. HC21 contains none of the ancient AS layers associated with early primate evolution which is present on other chromosomes, possibly due to the fact that the p-arm of HC21 and the other acrocentric chromosomes underwent substantial reorganization about 20 million years ago.