Neutral drift and polymorphism in gene-for-gene systems.
Neutral drift and polymorphism in gene-for-gene systems.
复制标题
基因对基因系统中的中性漂移和多态性。
作者：
M. Salathé;A. Scherer;S. Bonhoeffer
病原体是动植物进化的主要驱动力。抗病为寄主提供了高度的选择优势，但许多寄主-病原菌系统表现出显著的寄主抗性和病原菌毒力的多态。对这一现象最常见的解释是，抗性和毒性基因都很昂贵，当这些基因不必要时，就会有针对它们的选择。在这里，我们使用随机多位点模拟来表明，可以免费解释植物-病原菌系统中遗传多态的起源和维持。在多位点基因对基因系统中，超级病原菌的时间控制可以通过中性漂移导致抗性的多态。随着寄主种群中敏感等位基因数量的增加，除超级小种以外的病原菌类型能够引起侵染并入侵种群，导致病原菌多样性增加，进而导致寄主多样性增加。
Pathogens are a main driving force of the evolution of plants and animals. Being resistant to diseases confers a high selective advantage to hosts, yet many host-pathogen systems show a remarkable degree of polymorphism of host resistance and pathogen virulence. The most common explanation of this phenomenon is that both resistance and virulence genes are costly and that there is selection against those genes when they are unnecessary. Here, we use stochastic multi-locus simulations to show that the origin and the maintenance of genetic polymorphism in plant-pathogen systems can be explained without costs. In multi-locus gene-for-gene systems, temporal domination of a super pathogen can cause polymorphism in resistance through neutral drift. With an increasing number of susceptible alleles in the host population, pathogen types other than the super race are able to cause infections and invade the population, leading to higher pathogen diversity and in turn to higher host diversity.