Genomic Architecture of an Adaptive Radiation

本研究项目从两个角度探讨了脊椎动物多样化的遗传机制。第一个是群体遗传学。在新物种的进化过程中，有多少基因经历了不同的选择？它们在基因组中是如何分布的？第二个视角是发展演变的视角。哪些基因被修改以产生新的表型？马拉维湖大约800种亲缘关系密切的慈鲷是这项研究的理想模型系统。这些物种在颌和牙齿的形状、皮肤的颜色和性别决定机制上都有所不同。将对40个Metriaclima种群的基因组进行测序，以量化在姐妹物种之间分化的基因组比例。将对20个Labeotropheus种群的基因组进行测序，并与Metriaclima进行比较，以确定这些属之间在颅面形态上存在差异的基因组区域。这些数据将为脊椎动物物种形成和适应的基因组结构提供迄今为止最全面的图景。这些数据的分析将提高我们对控制神经嵴细胞发育的基因网络的理解，神经嵴细胞有助于各种各样的色素沉着和脊椎动物特有的颅面表型。该项目还将支持本科生进行原创研究的课程，以及高级研究人员分享分析慈鲷遗传和发育的最新方法的夏季研讨会。

This research project considers the genetic mechanisms of vertebrate diversification from two perspectives. The first is that of population genetics. How many genes experience divergent selection during the evolution of new species? How are they distributed across the genome? The second perspective is that of the evolution of development. Which genes are modified to produce new phenotypes? The flock of some 800 closely related cichlids fishes in Lake Malawi are an ideal model system for this study. These species differ in the shape of their jaws and teeth, the color of their skin, and their mechanisms of sex determination. The genomes of 40 Metriaclima populations will be sequenced to quantify the proportion of the genome that has diverged among sister species. The genomes of 20 Labeotropheus populations will be sequenced and compared to Metriaclima to identify regions of the genome that have diverged between these genera that differ in craniofacial morphology. These data will provide the most comprehensive picture ever produced of the genomic architecture of speciation and adaptation in vertebrates. Analysis of these data will improve our understanding of the gene network controlling the development of neural crest cells, which contribute to a wide variety of pigmentation and craniofacial phenotypes unique to vertebrates. The project will also support a class in which undergraduate students will perform original research, and a summer workshop in which senior researchers will share the latest methods for analysis of cichlid genetics and development.