Neocentrics and Holokinetics (Holocentrics): Chromosomes out of the Centromeric Rules
Neocentrics and Holokinetics (Holocentrics): Chromosomes out of the Centromeric Rules
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DOI：
10.1159/000314289
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发表时间：
2010-01-01
影响因子：
1.7
通讯作者：
Puertas, M. J.
中科院分区：
文献类型：
--
作者：
Guerra, M.;Cabral, G.;Puertas, M. J.
在大多数真核生物染色体中，着丝粒在有丝分裂中期表现为单一的缢痕。全动染色体是这一规则的例外，因为它们不显示任何着丝粒收缩。全动染色体在大多数关于着丝粒的评论中通常被遗忘，尽管它们存在于一些动物和植物物种中。它们通常与非常有趣和不寻常的有丝分裂和减数分裂机制有关。全动染色体与单着丝粒染色体的区别不仅在于动粒板的延伸，而且还在于许多其他特殊的核型特征，这可以被理解为“全动综合征”，本文对此进行了详细的综述。连同全动染色体，我们审查新着丝粒的活动，一个类似的有趣的情况下，该地区能够拉染色体向两极，而不显示的主要组成部分报告是必不可少的着丝粒功能。新着丝粒是指在结构、DNA序列和位置上不同于真正着丝粒的染色体区域，但在特殊情况下能够将染色体引导到细胞两极。新着丝粒在植物和动物中均有报道，表现出不同的特征。在人类和果蝇中，新着丝粒活动出现在具有缺陷染色体的体细胞中，缺乏功能性着丝粒。在大多数情况下，新着丝粒出现在具有正常着丝粒的染色体中，但仅在减数分裂期间活跃。由于自发或诱导的新着丝粒和全动染色体等例子，在进化中出现着丝粒的不同结构和DNA序列变得不那么令人惊讶了。版权所有（C）2010 S. Karger AG，巴塞尔
The centromere appears as a single constriction at mitotic metaphase in most eukaryotic chromosomes. Holokinetic chromosomes are the exception to this rule because they do not show any centromeric constrictions. Holokinetic chromosomes are usually forgotten in most reviews about centromeres, despite their presence in a number of animal and plant species. They are generally linked to very intriguing and unusual mechanisms of mitosis and meiosis. Holokinetic chromosomes differ from monocentric chromosomes not only in the extension of the kinetochore plate, but also in many other peculiar karyological features, which could be understood as the 'holokinetic syndrome' that is reviewed in detail. Together with holokinetic chromosomes we review neocentromeric activity, a similarly intriguing case of regions able to pull chromosomes towards the poles without showing the main components reported to be essential to centromeric function. A neocentromere is a chromosomal region different from the true centromere in structure, DNA sequence and location, but is able to lead chromosomes to the cell poles in special circumstances. Neocentromeres have been reported in plants and animals showing different features. Both in humans and Drosophila, neocentric activity appears in somatic cells with defective chromosomes lacking a functional centromere. In most cases in plants, neocentromeres appear in chromosomes which have normal centromeres, but are active only during meiosis. Because of examples such as spontaneous or induced neocentromeres and holokinetic chromosomes, it is becoming less surprising that different structures and DNA sequences of centromeres appear in evolution. Copyright (C) 2010 S. Karger AG, Basel