The Genetic Architecture of Adaptation in Laboratory Yeast Populations

0075594Zeyl适应的遗传学将在实验室酵母种群中进行研究，以测试种群如何对选择做出遗传反应的现有理论。每24小时，将来自每个群体的约200万个细胞转移到一管新鲜培养基中。随着细胞的繁殖，在这种环境中提高生长和生存的随机突变将传播，改变种群的遗传组成。每个种群每年经历大约2400代，允许观察到大量的遗传变化。每个种群的样本每隔100代就会被冷冻一次，这样每个种群的适应程度和基因就可以直接与其祖先的基因进行比较。使生物体适应其环境的适应性是生物学的核心特征，但在大多数生物体中，适应性无法在行动中观察到，也无法在遗传细节中进行研究。因此，一些基本问题仍然没有答案。例如，适应通常是涉及几个具有重大影响的突变，还是涉及许多具有轻微影响的突变？适应是一个可重复的过程，还是突变的随机性使每一个对选择的反应都是独特的？在这个项目中，将直接观察适应过程。强大的酵母遗传学技术将为基因如何使生物体与其环境相匹配提供新的见解。

0075594ZeylThe genetics of adaptation will be studied in laboratory yeast populations to test current theories of how populations respond genetically to selection. Every 24 hours, approximately 2 million cells from each population will be transferred to a tube of fresh medium. As the cells reproduce, random mutations that improve growth and survival in this environment will spread, changing the genetic makeup of the population. Each population undergoes about 2400 generations per year, allowing a substantial amount of genetic change to be observed. Samples of each population will be frozen every 100 generations, allowing both the degree of adaptation and the genes of each population to be compared directly to those of its ancestor.The adaptations that fit organisms to their environments are a central feature of biology, but in most organisms adaptation cannot be observed in action or studied in genetic detail. Some fundamental questions therefore remain unanswered. For example, does adaptation typically involve few mutations with major effects, or many mutations each with a slight effect? Is adaptation a reproducible process, or does the randomness of mutation make every response to selection unique? In this project the process of adaptation will be observed directly, as it occurs. The powerful techniques of yeast genetics will then provide new insight into how the genes match an organism to its environment.