Effects of Recombination on Hitchhiking Diversity in the Brassica Self-incompatibility Locus Complex
Effects of Recombination on Hitchhiking Diversity in the Brassica Self-incompatibility Locus Complex
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DOI：
10.1534/genetics.107.073825
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发表时间：
2007-10
期刊：
影响因子：
3.3
通讯作者：
Shohei Takuno;R. Fujimoto;Tetsu Sugimura;Keiichi Sato;S. Okamoto;Shaoling Zhang;T. Nishio
中科院分区：
文献类型：
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作者：
Shohei Takuno;R. Fujimoto;Tetsu Sugimura;Keiichi Sato;S. Okamoto;Shaoling Zhang;T. Nishio
在自交不亲和性中，通过频率依赖性选择来维持一些S单倍型，这导致反式特异性S单倍型。从SP 6到SP2的几个S位点（约40-60 kb），包括自交不亲和相关基因和一些邻近基因，在芜菁中由于搭便车效应而具有高度的核苷酸多样性，因此我们称这一区域为“S位点复合体”。S-位点复合体中的抑制被认为受到抑制。我们对B中三种S单倍型的S基因座复合体>50 kb的区域进行了测序。rapa和发现更高的核苷酸多样性在基因间区域比在编码区。在BrS-8和BrS-46之间发现了两个>10 kb的高度相似区域。利用B的反式特异性S单倍型（称为种间对）进行系统发育分析。rapa和B. oleracea的研究表明，重组降低了这两个区域的核苷酸多样性，并且SRK的S-位点复合体和激酶结构域中不参与自交不亲和的基因也经历了重组，但S结构域没有。分离可以减少S-位点复合物中的搭便车多样性，而从S结构域到SP11的区域将不利于重组。
In self-incompatibility, a number of S haplotypes are maintained by frequency-dependent selection, which results in trans-specific S haplotypes. The region of several kilobases (∼40–60 kb) from SP6 to SP2, including self-incompatibility-related genes and some adjacent genes in Brassica rapa, has high nucleotide diversity due to the hitchhiking effect, and therefore we call this region the “S-locus complex.” Recombination in the S-locus complex is considered to be suppressed. We sequenced regions of >50 kb of the S-locus complex of three S haplotypes in B. rapa and found higher nucleotide diversity in intergenic regions than in coding regions. Two highly similar regions of >10 kb were found between BrS-8 and BrS-46. Phylogenetic analysis using trans-specific S haplotypes (called interspecific pairs) of B. rapa and B. oleracea suggested that recombination reduced the nucleotide diversity in these two regions and that the genes not involved in self-incompatibility in the S-locus complex and the kinase domain, but not the S domain, of SRK have also experienced recombination. Recombination may reduce hitchhiking diversity in the S-locus complex, whereas the region from the S domain to SP11 would disfavor recombination.