Atypical centromeres in plants-what they can tell us.
Atypical centromeres in plants-what they can tell us.
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DOI：
10.3389/fpls.2015.00913
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发表时间：
2015
影响因子：
5.6
通讯作者：
Heckmann S
中科院分区：
文献类型：
--
作者：
Cuacos M;H Franklin FC;Heckmann S
着丝粒，作为凝聚中期染色体的初级缢痕可见，是基因组稳定性所必需的确定的染色体位点。它介导多蛋白质复合物（动粒）的瞬时组装，使其能够与纺锤体纤维相互作用，从而在核分裂期间忠实地分离遗传信息。着丝粒DNA在生物体之间的范围和序列组成不同，但几乎所有活性真核着丝粒的共同特征是存在着丝粒组蛋白H3变体cenH 3（a.k.a. CENP-A）。这些典型的着丝粒特征适用于大多数研究物种。然而，一些物种显示“非典型”着丝粒，如全着丝粒（着丝粒沿着几乎整个染色单体长度延伸）或新着丝粒（异位着丝粒活性）。在这篇综述中，我们提供了一个概述不同的非典型着丝粒类型，发现在植物中，包括holocentromeres，从头形成的着丝粒和终端新着丝粒以及二，三和metapolytromeres（一个以上的着丝粒每个染色体）。我们讨论了它们的具体和共同的特点，并将它们与其他真核生物中发现的着丝粒类型进行比较。我们还强调了在具有非典型着丝粒的植物中获得的对着丝粒生物学的新见解，例如定义全着丝粒的独特机制，减数分裂过程中具有全着丝粒的物种的特定适应或导致新着丝粒形成的各种情况。
The centromere, visible as the primary constriction of condensed metaphase chromosomes, is a defined chromosomal locus essential for genome stability. It mediates transient assembly of a multi-protein complex, the kinetochore, which enables interaction with spindle fibers and thus faithful segregation of the genetic information during nuclear divisions. Centromeric DNA varies in extent and sequence composition among organisms, but a common feature of almost all active eukaryotic centromeres is the presence of the centromeric histone H3 variant cenH3 (a.k.a. CENP-A). These typical centromere features apply to most studied species. However, a number of species display “atypical” centromeres, such as holocentromeres (centromere extension along almost the entire chromatid length) or neocentromeres (ectopic centromere activity). In this review, we provide an overview of different atypical centromere types found in plants including holocentromeres, de novo formed centromeres and terminal neocentromeres as well as di-, tri- and metapolycentromeres (more than one centromere per chromosomes). We discuss their specific and common features and compare them to centromere types found in other eukaryotic species. We also highlight new insights into centromere biology gained in plants with atypical centromeres such as distinct mechanisms to define a holocentromere, specific adaptations in species with holocentromeres during meiosis or various scenarios leading to neocentromere formation.