Evolution of Reproductive Isolation and Speciation in Neurospora

这项研究的目的是了解随着种群分化成不同的物种，杂交障碍是如何演变的。这个问题将通过研究两个地理上和遗传上隔离的粗糙脉孢子菌种群之间的杂交来解决，粗糙脉孢子菌是一种丝状真菌(霉菌)，是生物学中研究得最好的生物之一，粗糙脉孢子菌与它的近亲中间脉孢子菌之间的杂交将被解决。这个项目有两个主要目标。第一个是识别和测量在整个有性途径中进行的生殖隔离的个体成分，从杂交双亲之间交配互动的缺陷到杂交后代的死亡。第二个目标是绘制控制生殖隔离障碍的遗传基因座，并测试不同生物地理情景下生殖隔离的进化遗传学假说。生殖隔离的进化是新物种起源的关键事件，希望这项研究将增加我们对促进地球生物多样性的基本机制的了解。在脉孢子虫中，就像在许多物种中一样，生殖隔离的强度是由地理结构决定的：对于给定的物种对，来自不同地点的杂交亲本比来自相同地点的杂交亲本更容易受到干扰。这一观察表明，当物种一起出现时，针对杂交的自然选择加强了地理上孤立的物种之间进化的基线生殖隔离。在这里开展的工作旨在了解这一过程的遗传基础。

The object of the research is to understand how barriers to hybridization evolve as populations diverge into separate species. This problem will be addressed by studying hybrid crosses between two geographically and genetically isolated populations of Neurospora crassa, a filamentous fungus (mold) that is one of the best studied organisms in biology, and between N. crassa and its close relative N. intermedia. This project has two main goals. The first is to identify and measure the individual components of reproductive isolation operating throughout the sexual pathway, from defects in mating interactions between hybridizing parents to inviability of hybrid offspring. The second goal is to map genetic loci controlling reproductive isolation barriers and to test hypotheses about the evolutionary genetics of reproductive isolation under different biogeographic scenarios. The evolution of reproductive isolation is a key event in the origin of new species, and it is hoped that this research will add to our scant understanding of a foundational mechanism that promotes biodiversity on Earth. In Neurospora, as in many species, the intensity of reproductive isolation is geographically structured: for a given species pair, hybridizing parents from disparate locations are more interfertile than hybridizing parents from the same location. This observation suggests that baseline reproductive isolation evolving between geographically isolated species is reinforced by natural selection against hybridization when species occur together. The work undertaken here aims to understand the genetic basis of this process.