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根本来源，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，长期以来，果蝇一直是遗传学研究的模式生物。研究人员将研究三种果蝇，这些果蝇仅在过去5000-1.6万年内从一个共同的祖先物种分化而来。通过研究密切相关的物种，可以梳理出哪些遗传变化导致了最初的分离，哪些变化发生了后来的分离。特别是，该项目将确定哪些遗传差异与限制甚至阻止新分化物种之间杂交的交配行为和形态上的差异有关。该项目将为两所文科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研讨会。研究人员将通过测试两个关键预测来检验染色体倒置导致果蝇物种复合体分化和物种形成的假设：1)染色体倒置包含导致雄性求偶歌曲和雌性交配偏好不同的数量性状基因座，这是导致这些类群之间性别隔离的原因。2)与倒位外的基因组区域相比，染色体倒位表现出更大的序列差异。这项研究将直接测试染色体倒置是否包含导致性别隔离的表型，从而刺激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：物种间杂交以绘制行为物种表型的遗传图谱，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.