基于组学的蚊科昆虫高级阶元分子系统发育和进化研究

The family Culicidae is the medical insect group of the most importance, and the mosquito-borne disease is the main threat of human health. However, the classification system of the mosquito family is still very chaotic, which stems from the non-understanding of the phylogenetic relationships and evolution of higher-level taxa. In recent years, we have preliminarily conducted the studies on Culicidae taxonomy and evolutionary biology, and sequenced and comparatively analyzed the transcriptome and mitochondrial genome of some mosquito species. This project intends to carry out the following works: 1) sequence and analyze the transcriptome and mitochondrial genome of one representative species of each genus and subgenus in the family, respectively; 2) identify the shared orthologous single-copy genes of the known genome sequences of the family, extract the gene sequencers of the gene set from transcriptome sequences, and investigate the phylogenetic relationships and divergence times of genus-level taxa in the family; 3) make clear and extract the mitochondrial gene sequences that reflect mosquito evolution, based on the phylogenetic studies from genome and transcriptome sequences, and investigate the phylogenetic relationships and divergence times of subgenus-level taxa in the family based on the extracted sequences; 4) investigate the evolution of morphological characteristics and the way of historical biogeographical expansion of higher-level taxa in the family, through the morphological characteristics and biogeographical distribution investigation; and joining the phylogenetic study results based on genome, transcriptome and mitochondrial genomes; 5) establish the natural classification system and explain the biogeographic distribution pattern of the family, joining all these researches stated above. This project is of important theory and application significance for the taxonomy of the family, the elucidation of mosquito-borne disease transmission mechanism, and further the control of vector mosquitoes and mosquito-borne diseases.

蚊科是最重要的医学昆虫类群，蚊媒病是人类健康的主要威胁。然而，蚊科的分类系统仍很混乱，根源在于高级阶元的系统发育关系和进化尚不清楚。近年来，我们初步开展了蚊科的分类和进化生物学研究，测序和比较分析了部分蚊种的转录组和线粒体基因组。本项目拟开展下列工作：1）对蚊科属级和亚属级代表种分别开展转录组和线粒体基因组测序和分析工作；2）鉴定蚊虫基因组共有的单拷贝直系同源基因，研究蚊科属级阶元的系统发育关系和分歧时间；3）基于转录组的系统发育研究，弄清和提取反映蚊科进化的线粒体基因序列，并据此研究蚊科亚属级水平的系统发育关系和分歧时间；4）通过形态特征和地理分布研究，联合转录组和线粒体基因组系统发育研究结果，研究各高级阶元形态特征的进化及历史生物地理学特征；5）综合这些研究建立蚊科昆虫的自然分类系统，解释其生物地理学分布模式。这对于蚊科昆虫的分类学，最终控制媒介蚊虫及蚊媒病具有重要的理论和应用价值。

蚊科是最重要的医学昆虫类群，蚊媒病是人类健康的主要威胁。然而，蚊科的分类系统仍很混乱，根源在于高级阶元的系统发育关系和进化尚不清楚。近年来，我们初步开展了蚊科的分类和进化生物学研究，测序和比较分析了部分蚊种的转录组和线粒体基因组。本项目开展了下列工作：1）在四川、重庆、云南、浙江、广西、福建、海南等省系统地开展了蚊科昆虫的调查和采集，对采集的幼虫单只饲养出成虫，共采集标本20000余号，对所有标本开展了形态和分子鉴定，建设了亚洲储量最大的蚊科昆虫标本馆。2）对蚊科属级和亚属级具有代表性的108个种分别开展转录组和线粒体基因组测序、注释和分析工作。发现蚊科昆虫线粒体基因组的基因组成和顺序与祖先昆虫线粒体基因组一致，AT偏倚、长度变异和密码子使用与其他双翅目报道的线粒体基因组一致。3）鉴定了蚊虫基因组共有的单拷贝直系同源基因，研究了蚊科昆虫线粒体基因组的结构、基因构成、碱基组成、密码子使用偏向、基因的选择性压力、基因的重排、基因组的进化等特征。4）基于蚊科的转录组和线粒体基因序列，研究了蚊科蚊虫亚科、族、主要属和亚属、及部分种间的系统发育关系和分歧时间，讨论了蚊科昆虫的进化及历史生物地理学特征。研究结果表明按蚊亚科和伊蚊族, 库蚊族, 曼蚊族, 煞蚊族和巨蚊族是单系。伊蚊族和库蚊族是姐妹群，蓝带蚊族是(曼蚊族+ (巨蚊族+ 煞蚊族))的姐妹群。早侏罗世蚊类分化，白垩纪库蚊科大量辐射，与被子植物的出现、哺乳动物和鸟类的爆发相一致。这些工作对于蚊科昆虫的分类学发展，弄清蚊科昆虫的系统发育和进化，构建自然分类系统，最终有效控制媒介蚊虫及蚊媒病具有重要的理论和应用价值。.