Human artificial chromosomes with alpha satellite-based de novo centromeres show increased frequency of nondisjunction and anaphase lag
Human artificial chromosomes with alpha satellite-based de novo centromeres show increased frequency of nondisjunction and anaphase lag
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DOI：
10.1128/mcb.23.21.7689-7697.2003
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发表时间：
2003-11-01
影响因子：
5.3
通讯作者：
Willard, HF
中科院分区：
文献类型：
--
作者：
Rudd, MK;Mays, RW;Willard, HF
人类人工染色体已被用来模拟人类染色体分离的要求，并探索具有着丝粒功能的序列的性质。正常的人类着丝粒需要特殊的染色质，染色质由阿尔法卫星DNA与表观遗传修饰的组蛋白和着丝粒特异蛋白组成。虽然在人工染色体分析中，几种类型的α卫星DNA已被用来组装新的着丝粒，但它们在多大程度上完全概括了正常的着丝粒功能还没有被探索过。在这里，我们使用了两种阿尔法卫星DNA，DXZ1(来自X染色体)和D17Z1(来自17号染色体)，来产生人类人工染色体。虽然人工染色体在培养的几个月中是有丝分裂稳定的，但当我们使用后期试验检查它们在单个细胞分裂中的分离时，人工染色体表现出比自然人类染色体更多的分离错误(P<；0.001)。来自17号染色体和X染色体的自然发生但异常的小环染色体也比正常染色体错误分离更多，这意味着染色体总体大小和/或结构与染色体分离的保真度有关。由于不同的人工染色体在五倍的范围内错误分离，数据表明，不同的着丝粒DNA含量和/或表观遗传组装可以影响人工染色体的有丝分裂行为。
Human artificial chromosomes have been used to model requirements for human chromosome segregation and to explore the nature of sequences competent for centromere function. Normal human centromeres require specialized chromatin that consists of alpha satellite DNA complexed with epigenetically modified histones and centromere-specific proteins. While several types of alpha satellite DNA have been used to assemble de novo centromeres in artificial chromosome assays, the extent to which they fully recapitulate normal centromere function has not been explored. Here, we have used two kinds of alpha satellite DNA, DXZ1 (from the X chromosome) and D17Z1 (from chromosome 17), to generate human artificial chromosomes. Although artificial chromosomes are mitotically stable over many months in culture, when we examined their segregation in individual cell divisions using an anaphase assay, artificial chromosomes exhibited more segregation errors than natural human chromosomes (P < 0.001). Naturally occurring, but abnormal small ring chromosomes derived from chromosome 17 and the X chromosome also missegregate more than normal chromosomes, implicating overall chromosome size and/or structure in the fidelity of chromosome segregation. As different artificial chromosomes missegregate over a fivefold range, the data suggest that variable centromeric DNA content and/or epigenetic assembly can influence the mitotic behavior of artificial chromosomes.