A fine-structure map of spontaneous mitotic crossovers in the yeast Saccharomyces cerevisiae.
A fine-structure map of spontaneous mitotic crossovers in the yeast Saccharomyces cerevisiae.
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DOI：
10.1371/journal.pgen.1000410
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发表时间：
2009-03
期刊：
影响因子：
4.5
通讯作者：
Petes TD
中科院分区：
文献类型：
--
作者：
Lee PS;Greenwell PW;Dominska M;Gawel M;Hamilton M;Petes TD
同源重组是有丝分裂细胞DNA损伤修复的重要机制。具有杂合等位基因的同源物之间的有丝分裂交叉可以产生两个纯合子子细胞（杂合性丢失），而非同源染色体上的重复基因之间的交叉可以导致易位。使用的遗传系统，允许选择的子细胞，包含有丝分裂交叉的相互产品，我们映射的交叉和基因转换事件在约4 kb的分辨率在120 kb的区域的染色体V的酿酒酵母。与有丝分裂交换相关的基因转换区比与减数分裂重组相关的转换区长得多（平均约12 kb），并且非随机地沿着染色体分布。此外，约40%的转换事件具有标记分离的模式，其最简单地解释为反映了在细胞周期的G1中断裂的染色体的修复。大多数高等生物都有两个不同类型的染色体副本。例如，人类女性有23对染色体。虽然染色体对具有非常相似的序列，但它们并不相同。染色体对的成员可以将片段从一条染色体交换到另一条染色体;这些交换被称为“重组”。以前大多数关于重组的研究都是在经历减数分裂的细胞中进行的，减数分裂是导致卵子和精子（配子）形成的过程。然而，在有丝分裂的细胞中也可以发生分裂。在我们的研究中，我们研究了酵母中有丝分裂重组的性质。我们表明，有丝分裂重组不同于减数分裂重组在两个重要方面。首先，在有丝分裂重组过程中，非染色体转移的染色体片段的大小比在减数分裂交换过程中转移的染色体片段大得多。其次，在减数分裂中，大多数重组事件涉及单个染色体断裂的修复，而在有丝分裂中，大约一半的重组事件似乎涉及两个染色体断裂的修复。
Homologous recombination is an important mechanism for the repair of DNA damage in mitotically dividing cells. Mitotic crossovers between homologues with heterozygous alleles can produce two homozygous daughter cells (loss of heterozygosity), whereas crossovers between repeated genes on non-homologous chromosomes can result in translocations. Using a genetic system that allows selection of daughter cells that contain the reciprocal products of mitotic crossing over, we mapped crossovers and gene conversion events at a resolution of about 4 kb in a 120-kb region of chromosome V of Saccharomyces cerevisiae. The gene conversion tracts associated with mitotic crossovers are much longer (averaging about 12 kb) than the conversion tracts associated with meiotic recombination and are non-randomly distributed along the chromosome. In addition, about 40% of the conversion events have patterns of marker segregation that are most simply explained as reflecting the repair of a chromosome that was broken in G1 of the cell cycle. Most higher organisms have two copies of several different types of chromosomes. For example, the human female has 23 pairs of chromosomes. Although the chromosome pairs have very similar sequences, they are not identical. Members of a chromosome pair can swap segments from one chromosome to the other; these exchanges are called “recombination.” Most previous studies of recombination have been done in cells undergoing meiosis, the process that leads to the formation of eggs and sperm (gametes). Recombination, however, can also occur in cells that are dividing mitotically. In our study, we examine the properties of mitotic recombination in yeast. We show that mitotic recombination differs from meiotic recombination in two important ways. First, the sizes of the chromosome segments that are non-reciprocally transferred during mitotic recombination are much larger than those transferred during meiotic exchange. Second, in meiosis, most recombination events involve the repair of a single chromosome break, whereas in mitosis, about half of the recombination events appear to involve the repair of two chromosome breaks.
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映射减数分裂的单链DNA揭示了酿酒酵母中DNA双链断裂的新景观。
影响因子：
9.8
作者：
Buhler, Cyril;Borde, Valerie;Lichten, Michael
通讯作者：
Lichten, Michael
影响因子：
11.4
作者：
Aylon, Y;Liefshitz, B;Kupiec, M
通讯作者：
Kupiec, M
DOI：
10.1073/pnas.84.22.8035
发表时间：
1987-11-01
影响因子：
11.1
作者：
ATCHESON, CL;DIDOMENICO, B;ELDER, RT
通讯作者：
ELDER, RT
DOI：
10.1073/pnas.75.9.4436
发表时间：
1978-01-01
影响因子：
11.1
作者：
ESPOSITO, MS
通讯作者：
ESPOSITO, MS
影响因子：
5.3
作者：
BISHOP, DK;KOLODNER, RD
通讯作者：
KOLODNER, RD