Self‐incompatibility (SI) is a self‐recognition genetic system enforcing outcrossing in hermaphroditic flowering plants and results in one of the arguably best understood forms of natural (balancing) selection maintaining genetic variation over long evolutionary times. A rich theoretical and empirical population genetics literature has considerably clarified how the distribution of SI phenotypes translates into fitness differences among individuals by a combination of inbreeding avoidance and rare‐allele advantage. At the same time, the molecular mechanisms by which self‐pollen is specifically recognized and rejected have been described in exquisite details in several model organisms, such that the genotype‐to‐phenotype map is also pretty well understood, notably in the Brassicaceae. Here, we review recent advances in these two fronts and illustrate how the joint availability of detailed characterization of genotype‐to‐phenotype and phenotype‐to‐fitness maps on a single genetic system (plant self‐incompatibility) provides the opportunity to understand the evolutionary process in a unique perspective, bringing novel insight on general questions about the emergence, maintenance, and diversification of a complex genetic system.

中文翻译：

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十字花科自交不亲和的进化：自然选择教科书例子的教训。


自交不亲和性（SI）是一种自我识别遗传系统，在雌雄同体开花植物中强制进行异交，并导致可以说是最容易理解的自然（平衡）选择形式之一，在漫长的进化过程中维持遗传变异。丰富的理论和实证群体遗传学文献已经相当阐明了 SI 表型的分布如何通过近交避免和稀有等位基因优势的结合转化为个体之间的适应性差异。与此同时，自体花粉被特异性识别和拒绝的分子机制已经在几种模型生物中得到了详尽的描述，因此基因型到表型图谱也得到了很好的理解，特别是在十字花科植物中。在这里，我们回顾了这两个领域的最新进展，并说明了在单一遗传系统（植物自交不亲和性）上基因型到表型和表型到适应性图的详细表征的联合可用性如何提供了理解进化过程的机会。以独特的视角进行过程，为有关复杂遗传系统的出现、维持和多样化的一般问题带来新颖的见解。