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

该项目将调查一群已知传播疾病的蚊子中驱动物种形成的遗传机制。在这一群蚊子中，不同种类的数量传统上被低估了，因为尽管在外观上无法区分，但这一群蚊子实际上是由多个基因上不同的物种组成的。尽管它们对人类很重要，但人们对这些物种的起源知之甚少。这个项目解决了蚊子遗传学中的三个问题。首先，哪些基因导致了物种间的生殖隔离？其次，这些基因是如何随着时间的推移而分化，从而导致物种形成的？第三，两个物种之间的变化模式在不同的物种对之间是否一致？其中一些物种是撒哈拉以南非洲人类疟疾的主要媒介。除了帮助我们了解创造生物多样性的遗传过程之外，该项目还具有额外的社会效益，因为它可以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（Anopheles gambiae）这个名字实际上与一个物种复合体有关，这个物种由8个基因不同但最近才分化的物种组成，无法根据形态学来识别。该复合体是物种形成遗传学领域的一个重要研究系统，因为复合体中的物种表现出广泛的遗传分化，包括部分分离的亚种。因此，这种物种复合体使这些研究人员能够研究物种形成的过程。当不同种类的复合体杂交时，雄性后代不育，雌性后代可育。如果一个杂交的雌性与任何一个亲本物种的雄性交配，产生的第二代杂种由于遗传不相容而表现出不同程度的不育。这就允许通过对许多回交后代的测序来绘制不育原因的基因组图谱。因此，这项研究将绘制出导致两个物种之间回交杂交种雄性和雌性不育的基因组区域。冈比亚和安哥拉。quadriannulatus)。结合已有的安、安两种回交杂交种的雌雄不育性资料。冈比亚和安哥拉。这些数据将确定相同的基因组区域是否会导致不同物种对的不育。通过比较多个物种对的分化模式及其原因，这项研究将增加我们对一个重要动物群体中驱动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.