Natural variation in expression of self-incompatibility in Arabidopsis thaliana:: Implications for the evolution of selfing
Natural variation in expression of self-incompatibility in Arabidopsis thaliana:: Implications for the evolution of selfing
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DOI：
10.1073/pnas.0406970101
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发表时间：
2004-11-09
影响因子：
11.1
通讯作者：
Nasrallah, JB
中科院分区：
文献类型：
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作者：
Nasrallah, ME;Liu, P;Nasrallah, JB
从异交到自交交配系统的转变是植物繁殖中最普遍的进化趋势之一，人们认为这种趋势在开花植物中重复发生。然而，关于自我繁殖的进化和自交的遗传结构，人们知之甚少。在这里，我们建立了一个用于十字花科植物向自交可育性转换的遗传分析模型，其中祖先的异交方式由自交不亲和性(SI)决定，自交不亲和性是由S基因控制的遗传系统。我们发现拟南芥生态型表现出S基因座的多态，并且在转化来自专性异交拟南芥的S基因座后表现出不同的表达S1性状的能力。值得注意的是，至少有一个生态型恢复到与自然自交不亲和物种相同的稳定的自交不亲和表型。这些生态型差异是可遗传的，反映了不同的拟南星种群对导致或强制转换为自交可育的独立突变的固定。他们的持续分析有望确定作为自交自然选择目标的基因座，并有助于对Sl反应的机械性理解。
The switch from an out-crossing to a self-fertilizing mating system is one of the most prevalent evolutionary trends in plant reproduction and is thought to have occurred repeatedly in flowering plants. However, little is known about the evolution of self-fertility and the genetic architecture of selfing. Here, we establish Arabidopsis thaliana as a model for genetic analysis of the switch to self-fertility in the crucifer family, where the ancestral out-crossing mode of mating is determined by self-incompatibility (SI), a genetic system controlled by the S locus. We show that A. thaliana ecotypes exhibit S-locus polymorphisms and differ in their ability to express the Sl trait upon transformation with S-locus genes derived from the obligate out-crosser Arabidopsis lyrata. Remarkably, at least one ecotype was reverted to a stable, self-incompatible phenotype identical to that of naturally self-incompatible species. These ecotype differences are heritable and reflect the fixation in different A. thaliana populations of independent mutations that caused or enforced the switch to self-fertility. Their continued analysis promises to identify the loci that were the targets of natural selection for selfing and to contribute to a mechanistic understanding of the Sl response.