Homoeologous nonreciprocal recombination in polyploid cotton
Homoeologous nonreciprocal recombination in polyploid cotton
复制标题
DOI：
10.1111/j.1469-8137.2009.03093.x
复制
发表时间：
2010-01-01
期刊：
影响因子：
9.4
通讯作者：
Wendel, Jonathan F.
中科院分区：
文献类型：
--
作者：
Salmon, Armel;Flagel, Lex;Wendel, Jonathan F.
多倍体的形成和产生部分基因组复制的过程产生了冗余的基因组信息，其命运是进化生物学家特别感兴趣的。不同的过程可以导致重复基因之间的多样性，这可能是抵消的机制，延迟分歧，包括基因转换通过非互惠同源异源交换。arboreum（A genome），G. raimondii（D基因组）和G.我们估计了G. hirsutum（AD基因组）中重叠群的比例，从而使我们能够鉴定出指示潜在同源互换的同源单核苷酸多态性。自100 - 200万年前多倍体棉花起源以来经历了非互惠同源交换的陆地棉（Mya）的比例在1.8%和1.9%之间。为了解决基因组间交换何时发生的问题，我们分析了所有5个棉花异源多倍体中受同源重组影响的6个基因，采用系统发育方法，分析表明，非互惠同源重组交换发生在整个多倍体分化和物种形成过程中，而不是突变与多倍体形成。此外，一些基因组区域显示物种间同源重组的多种模式。
P>Polyploid formation and processes that create partial genomic duplication generate redundant genomic information, whose fate is of particular interest to evolutionary biologists. Different processes can lead to diversification among duplicate genes, which may be counterbalanced by mechanisms that retard divergence, including gene conversion via nonreciprocal homoeologous exchange.Here, we used genomic resources in diploid and allopolyploid cotton (Gossypium) to detect homoeologous single nucleotide polymorphisms provided by expressed sequence tags from G. arboreum (A genome), G. raimondii (D genome) and G. hirsutum (AD genome), allowing us to identify homoeo-single nucleotide polymorphism patterns indicative of potential homoeologous exchanges.We estimated the proportion of contigs in G. hirsutum that have experienced nonreciprocal homoeologous exchanges since the origin of polyploid cotton 1-2 million years ago (Mya) to be between 1.8% and 1.9%. To address the question of when the intergenomic exchange occurred, we assayed six of the genes affected by homoeo-recombination in all five Gossypium allopolyploids using a phylogenetic approach.This analysis revealed that nonreciprocal homoeologous exchanges have occurred throughout polyploid divergence and speciation, as opposed to saltationally with polyploid formation. In addition, some genomic regions show multiple patterns of homoeologous recombination among species.