Collaborative research, RUI, SG: Phenotypic and genomic patterns of divergence across a young Drosophila species complex.

这项研究将促进我们对物种形成过程的理解，即一个物种分裂成两个物种。这一过程是生物多样性的基本来源，但仍未得到很好的理解。这个项目将帮助我们了解基因、行为和形态上的变化，这些变化使新物种能够彼此完全区分开来。这项研究的重点是果蝇，它们长期以来一直被用作遗传学研究的模式生物。研究人员将研究三种果蝇，这三种果蝇仅在过去5000 - 16000年间才从一个共同的祖先物种中分化出来。通过研究密切相关的物种，有可能梳理出哪些基因变化导致了最初的分离，哪些变化是后来发生的。特别是，该项目将确定哪些遗传差异与交配行为和形态的差异有关，这些差异限制甚至阻止了新分化物种之间的杂交。该项目将为两所文理学院的本科生提供研究经验，并对他们进行DNA测序和基因分析方面的培训。此外，研究结果将用于培训高中教师，并在纽约州北部和马萨诸塞州西部发展科学教育讲习班。研究人员将通过测试两个关键预测来验证染色体倒位导致了果蝇物种复合体的分化和物种形成的假设：1)染色体倒位包含了不同的雄性求偶歌曲和雌性交配偏好的数量性状位点，这是导致这些分类群之间性隔离的原因。2)与染色体倒位外的基因组区域相比，染色体倒位显示出更大的序列差异。本研究将直接检测染色体倒位是否存在导致性隔离的表型，从而导致新生物种之间的基因流动减少，从而促进基因组分化和物种形成的过程。将收集两个数据集：种间杂交以绘制行为物种形成表型的遗传图谱，以及覆盖每个行为物种整个地理范围的种群基因组数据。

This study will advance our understanding of the process of speciation, the splitting of one species into two. This process is the fundamental source of biodiversity and yet is still not well understood. This project will help us understand the genetic, behavioral, and morphological changes that allowed new species to fully differentiate from one another. The research focuses on fruit flies, which have long served as a model organism for studies of genetics. The researchers will study three species of fruit flies that diverged from a common ancestor species only in the last 5,000-16,000 years. By studying closely related species, it is possible to tease apart which genetic changes led to the original separation versus which changes happened afterwards. In particular, the project will identify what genetic differences are associated with differences in mating behavior and morphology that restrict or even prevent interbreeding between newly diverged species. The project will provide research experiences for undergraduate students at two liberal arts colleges and train them in DNA sequencing and genetic analysis. Further, the research findings will be used to train high school teachers and develop science educational workshops in upstate New York and western Massachusetts.The researchers will test the hypothesis that chromosomal inversions have caused divergence and speciation in the Drosophila athabasca species complex by testing two key predictions: 1) Chromosomal inversions contain Quantitative Trait Loci for divergent male courtship song and female mating preferences that are responsible for sexual isolation between these taxa. 2) Chromosomal inversions show greater sequence divergence compared to genomic regions outside of the inversions. This study will directly test if chromosomal inversions harbor phenotypes that cause sexual isolation and thereby instigated reduction in gene flow between nascent species, thus facilitating the process of genomic divergence and speciation. Two datasets will be collected: inter-species crosses to genetically map behavioral speciation phenotypes and population genomic data covering the entire geographical range of each behavioral species.