Quantitative dynamics of telomere bouquet formation.
Quantitative dynamics of telomere bouquet formation.
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DOI：
10.1371/journal.pcbi.1002812
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发表时间：
2012
影响因子：
4.3
通讯作者：
Howard M
中科院分区：
文献类型：
--
作者：
Richards DM;Greer E;Martin AC;Moore G;Shaw PJ;Howard M
作为重组的前奏，同源染色体在减数分裂过程中配对的机制一直是个谜。在减数分裂时，许多生物体中的端粒附着在核膜上，并一起移动形成端粒束，可能是为了促进同源搜索。据信，单独的扩散不足以解释花束的形成，还需要一些定向运动。在这里，我们认为在小麦黑麦杂交实验和使用数学建模的端粒花束的形成。小麦核的大尺寸和小麦的商业重要性使得小麦中的染色体配对成为一个特别有趣和重要的过程，这可能很好地揭示了其他生物中的配对。我们发现，在花束形成之前，姐妹染色单体端粒总是附着在核膜的半球上，并且倾向于成对地结合。我们研究了一个突变体缺乏Ph 1位点，一个位点，确保正确的同源染色体配对，并发现花束形成延迟在野生型相比，突变体。此外，我们开发了一个数学模型的花束形成涉及扩散和定向运动，在那里我们表明，定向运动本身就足以解释花束形成动力学。十亿年前有性生殖的出现导致了生物体如何将遗传物质传递给后代的革命。在有性生殖的生物中，双亲二倍体细胞含有两个几乎相同的染色体拷贝（同源物），产生的配子只含有一个染色体拷贝。这反过来又需要配对相关的同源染色体，以确保它们随后分离到配子中。由于染色体必须在整个细胞核中寻找它们的同源配偶体，因此对这种配对是如何实现的还知之甚少。许多生物体将每条染色体（端粒）的末端沿着细胞核的外围移动到一小片中，形成端粒束。我们在这里表明，直接运动的端粒对花束网站，可能由分子马达驱动，可以解释花束形成动力学。我们特别关注小麦-黑麦杂交种，因为了解小麦中的同源配对可能对通过帮助杂交种的生产来培育抗性作物产生深远的影响。我们还表明，小麦似乎已经进化出一种机制，以延迟端粒花束形成的开始，也许是为了确保染色体找到正确的同源伴侣。
The mechanism by which homologous chromosomes pair during meiosis, as a prelude to recombination, has long been mysterious. At meiosis, the telomeres in many organisms attach to the nuclear envelope and move together to form the telomere bouquet, perhaps to facilitate the homologous search. It is believed that diffusion alone is not sufficient to account for the formation of the bouquet, and that some directed movement is also required. Here we consider the formation of the telomere bouquet in a wheat-rye hybrid both experimentally and using mathematical modelling. The large size of the wheat nucleus and wheat's commercial importance make chromosomal pairing in wheat a particularly interesting and important process, which may well shed light on pairing in other organisms. We show that, prior to bouquet formation, sister chromatid telomeres are always attached to a hemisphere of the nuclear membrane and tend to associate in pairs. We study a mutant lacking the Ph1 locus, a locus ensuring correct homologous chromosome pairing, and discover that bouquet formation is delayed in the wild type compared to the mutant. Further, we develop a mathematical model of bouquet formation involving diffusion and directed movement, where we show that directed movement alone is sufficient to explain bouquet formation dynamics. The appearance of sexual reproduction over a billion years ago led to a revolution in how organisms pass on genetic material to their offspring. In sexually reproducing organisms parental diploid cells, containing two nearly identical copies of each chromosome (homologues), produce gametes containing only one copy of each chromosome. This in turn requires the pairing of the related homologous chromosomes to ensure their subsequent segregation into the gametes. How this pairing is achieved is poorly understood since chromosomes must search the entire nucleus for their homologous partner. Many organisms move the ends of each chromosome (the telomeres) along the periphery of the nucleus into a small patch forming the telomere bouquet. We show here that direct movement of telomeres towards the bouquet site, potentially driven by molecular motors, can explain bouquet formation dynamics. We focus in particular on a wheat-rye hybrid since understanding homologous pairing in wheat could have profound implications for breeding resistant crops by aiding the production of hybrids. We also show that wheat seems to have evolved a mechanism to delay the onset of telomere bouquet formation, perhaps in order to ensure chromosomes find their correct homologous partners.
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DOI：
10.1073/pnas.0801521105
发表时间：
2008-04-22
影响因子：
11.1
作者：
Colas, Isabelle;Shaw, Peter;Moore, Graham
通讯作者：
Moore, Graham
影响因子：
14.8
作者：
Prieto, Pilar;Moore, Graham;Shaw, Peter
通讯作者：
Shaw, Peter
影响因子：
7.2
作者：
Martinez-Perez, E;Shaw, P;Moore, G
通讯作者：
Moore, G
影响因子：
4.2
作者：
COX, AV;BENNETT, ST;BENNETT, MD
通讯作者：
BENNETT, MD
影响因子：
4
作者：
Cowan, CR;Cande, WZ
通讯作者：
Cande, WZ