DISSERTATION RESEARCH: The Genomics of Hybrid Sterility & Speciation in the Anopheles gambiae Species Complex

该项目将研究一组已知可传播疾病的蚊子物种形成的遗传机制。在这组蚊子中，不同物种的数量传统上被低估了，因为尽管在外观上难以区分，但这一组蚊子实际上是由多个遗传上不同的物种组成的。尽管它们对人类很重要，但人们对这些物种是如何产生的知之甚少。这个项目解决了蚊子遗传学中的三个问题。首先，哪些基因负责物种之间的生殖隔离？第二，这些基因如何随着时间的推移而分化，导致物种形成？第三，两个物种之间的变化模式在不同的物种对中是否一致？其中几个物种是撒哈拉以南非洲人类疟疾的主要传播媒介。因此，除了帮助我们了解创造生物多样性的遗传过程外，该项目还具有额外的社会效益，因为它可能通过识别导致蚊子不育的基因来帮助开发和实施新的遗传媒介控制措施。冈比亚按蚊的名字实际上与一个物种复合体有关，该物种由8个遗传上不同但最近分化的物种组成，这些物种无法根据形态进行识别。该复合体是物种形成遗传学领域的一个重要研究系统，因为该复合体中的物种表现出广泛的遗传差异，包括部分孤立的亚种。因此，这种物种复合体使这些研究人员能够在物种形成展开时研究物种形成。当不同物种的复合体杂交时，雄性后代是不育的，雌性是可育的。如果杂交雌性与父本物种的雄性交配，所产生的第二代杂交后代由于遗传不亲和性而表现出不同程度的不育性。这使得可以通过对许多回交后代进行测序来绘制不育原因的基因组图谱。因此，这项研究将绘制导致两个物种之间回交杂种雄性和雌性不育的基因组区域。冈比亚亚纲和An.四环虫)。结合已有的回交雄性和雌性不育性的数据。冈比亚亚纲和An.这一数据将确定相同的基因组区域是否会导致不同物种之间的不育。通过比较多个物种对的差异模式及其原因，这项研究将增加我们对推动一个重要动物群体物种形成的因素的理解。

This project will investigate genetic mechanisms driving speciation in a group of mosquitos known to transmit disease. In this group of mosquitos the number of different species has traditionally been underestimated because, while indistinguishable in appearance, the group is actually comprised of multiple genetically distinct species. Despite their importance to humans little is known about how these species arose. This project addresses three questions in mosquito genetics. First what genes are responsible for reproductive isolation between the species? Second, how do those genes diverge across time leading to speciation? And third is the pattern of change between two species consistent across different pairs of species? Several of these species are the major vectors of human malaria in sub-Saharan Africa. In addition to helping us understand the genetic process that creates biological diversity, this project therefore has additional societal benefits as it may help in the development and implementation of novel genetic vector control measures by, identifying genes causing sterility in mosquitoes.The name Anopheles gambiae is actually associated with a species complex of eight genetically distinct but recently diverged species that cannot be identified based on morphology. The complex is an important study system for the field of speciation genetics because species in the complex exhibit a wide range of genetic divergence, including partially isolated sub-species. Therefore this species complex allows these researchers to study speciation as it unfolds. When different species of the complex hybridize, the male offspring are sterile and females are fertile. If a hybrid female mates with a male of either parental species, the resulting second-generation hybrids exhibit varying levels of sterility due to genetic incompatibility. This allows genomic mapping of the causes of sterility through sequencing of many backcross offspring. This study will thereby map regions of the genome that cause male and female sterility in backcross hybrids between two species (An. gambiae and An. quadriannulatus). Combined with existing data on male and female sterility in backcross hybrids between An. gambiae and An. arabiensis this data will determine if the same genomic regions cause sterility across different species pairs. By comparing the patterns of divergence and their causes across multiple species pairs the research will increase our understanding of the factors driving speciation in an important group of animals.