Molecular mechanism of natural variation and adaptation of circadian clock

 描述(由申请人提供) 由于地球自转，地球上的大多数生物都适应了24小时的循环环境。生物体知道一天中的时间，准备迎接到来的非生物和生物压力，并利用周围环境的预期变化。生物体的这种时间测量机制是其在自然界中生存的重要生物学功能。具有大约24小时周期的可观察的生物节律统称为昼夜节律，其潜在的分子机制称为昼夜节律时钟。在不同的模式生物中，已经提出昼夜节律是一种健康特征。然而，我们仍然缺乏关于生物钟如何实现健身优势的知识。该提案中的研究人员已经确定了北美菌株和其他大陆菌株中离散脉孢菌复杂系统发育物种4b(PS4b)的大陆特有时钟变异，并建议利用遗传学、基因组学、蛋白质组学和计算生物学工具来表征适应基因的等位基因变异如何导致时钟表型的变异以适应其独特的栖息地。他们将产生基因完全相同的等位基因互换菌株，除了 候选基因的大陆特有等位基因。将通过测量不同栖息地条件下的后代数量来测试候选基因的适应值。这项拟议研究的成功结果将使我们深入了解生物体昼夜节律的局部适应如何影响生物体的适应性。

 DESCRIPTION (provided by applicant) Most living organisms on earth are adapted to a 24 hr cycling environment due to the rotation of the earth. An organism knows the time of the day and prepares the incoming abiotic and biotic stresses, and also utilizes the expected changes of ambient environment. This time-measuring mechanism in an organism is an important biological function for its survival in nature. The observable biological rhythm with about a 24 hr period is collectively called circadian rhythm, and the underlying molecular mechanism of circadian rhythm is called the circadian clock. It has been suggested in different model organisms that circadian rhythm is a fitness trait. However, we still lack knowledge in regards to how circadian clock achieves the fitness advantage. Researchers in the proposal have identified Continent-Specific-Clock-Variation in Neurospora discreta species complex Phylogenetic Species 4b (PS4b) in strains collected in North American strains in comparison to strains collected from other continents, and proposed to characterize how allelic variations of the adaptive gene causes variation of the clock phenotype to adapt to their unique habitat using genetics, genomics, proteomics, and computational biology tools. They will generate allele-swap strains where their genotype is identical, except the continent-specific allele of the candidate gene. The fitness value of the candidate gene will be tested by measuring the number of progeny under different habitat conditions. The successful outcome of the proposed study will allow us an insight on how a local adaption of circadian rhythm of an organism influences the organism's fitness.