Mechanisms of ectopic gene conversion.
Mechanisms of ectopic gene conversion.
复制标题
DOI：
10.3390/genes1030427
复制
发表时间：
2010-11-29
期刊：
影响因子：
3.5
通讯作者：
Hastings PJ
中科院分区：
文献类型：
--
作者：
Hastings PJ
基因转换（转换），DNA序列信息的单向转移，作为断裂或受损DNA分子重组修复的副产品发生。切除修复过程通过从双链体DNA的未受损链复制互补序列来替换受损的DNA，而重组机制通常在另一个分子中复制相似的序列来替换受损的序列。在有丝分裂细胞中，另一个分子通常是姐妹染色单体，修复不会导致遗传变化。较少使用异位位置的同源染色体或同源序列。转化通过两种方式从修复中产生。首先，如果在断裂位点处存在双链缺口，则同源序列将用作合成的模板以填充差距，从而在两条链中传递序列信息。其次，重组修复使用互补碱基配对，并且如此形成的异源双链分子是转化的来源，无论是作为异源双链还是当在异源双链中错配碱基校正后保留供体（未受损模板）信息时。存在有利于使用姐妹分子的机制，其在可以使用异位同源性之前必须失效。减数分裂重组事件导致形成减数分裂中所需的交换，以使同源染色体对有序分离。这些事件的程序性双链断裂的重组修复的结果，但有丝分裂重组相比，减数分裂重组事件主要发生在同源染色体之间，因此，通过转换转移序列差异是非常频繁的。不形成交叉的瞬时重组事件在同源染色体之间和异位同源性区域之间形成，并在频繁的非交叉转换（包括异位转换）的发生中留下它们的标记。
Gene conversion (conversion), the unidirectional transfer of DNA sequence information, occurs as a byproduct of recombinational repair of broken or damaged DNA molecules. Whereas excision repair processes replace damaged DNA by copying the complementary sequence from the undamaged strand of duplex DNA, recombinational mechanisms copy similar sequence, usually in another molecule, to replace the damaged sequence. In mitotic cells the other molecule is usually a sister chromatid, and the repair does not lead to genetic change. Less often a homologous chromosome or homologous sequence in an ectopic position is used. Conversion results from repair in two ways. First, if there was a double-strand gap at the site of a break, homologous sequence will be used as the template for synthesis to fill the gap, thus transferring sequence information in both strands. Second, recombinational repair uses complementary base pairing, and the heteroduplex molecule so formed is a source of conversion, both as heteroduplex and when donor (undamaged template) information is retained after correction of mismatched bases in heteroduplex. There are mechanisms that favour the use of sister molecules that must fail before ectopic homology can be used. Meiotic recombination events lead to the formation of crossovers required in meiosis for orderly segregation of pairs of homologous chromosomes. These events result from recombinational repair of programmed double-strand breaks, but in contrast with mitotic recombination, meiotic recombinational events occur predominantly between homologous chromosomes, so that transfer of sequence differences by conversion is very frequent. Transient recombination events that do not form crossovers form both between homologous chromosomes and between regions of ectopic homology, and leave their mark in the occurrence of frequent non-crossover conversion, including ectopic conversion.
登录
查看更多内容
影响因子：
64.8
作者：
通讯作者：
--
影响因子：
64.5
作者：
Denamur, E;Lecointre, G;Matic, I
通讯作者：
Matic, I
影响因子：
4.8
作者：
Kim, JS;Krasieva, TB;Yokomori, K
通讯作者：
Yokomori, K
影响因子：
64.8
作者：
Mancera, Eugenio;Bourgon, Richard;Brozzi, Alessandro;Huber, Wolfgang;Steinmetz, Lars M.
通讯作者：
Steinmetz, Lars M.
影响因子：
14.9
作者：
BIRKENBIHL, RP;SUBRAMANI, S
通讯作者：
SUBRAMANI, S