Mechanism and application of male determination in aedine mosquitoes

伊蚊雄性判定机制及应用

• 批准号: 9081697
• 负责人: Zhijian Jake Tu
• 金额: $ 61.4万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-03 至 2021-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9081697
• 关键词: Aedes; Anopheles Genus; BCL2/Adenovirus E1B 19kd Interacting Protein 3-Like; Biological Assay; Biology; Blood; CRISPR/Cas technology; Chikungunya virus; Chromosomes; Culex (Genus); Culicidae; Dengue; Development; Disease Outbreaks; Distant; Drosophila melanogaster; Ectopic Expression; Embryo; Equilibrium; Evolution; Exhibits; Female; Florida; Foundations; Future; Gene Targeting; Genes; Genetic; Genome; Health; Homologous Gene; Incidence; Insecta; Insecticide Resistance; Knock-out; Knowledge; Link; Male Genital Organs; Methods; Minor Lymphocyte Stimulatory Loci; Molecular; Mosquito Control; Mosquito-borne infectious disease; Order Coleoptera; Organism; Pathway interactions; Population; Prevention; Production; Property; Protein Isoforms; Proteins; RNA; RNA Binding; RNA Splicing; Refractory Disease; Research; Risk; Staging; Sterility; System; Testing; Tetanus Helper Peptide; Transgenes; Transgenic Organisms; Translating; Y Chromosome; Yellow Fever; base; chikungunya; feeding; fly; improved; male; novel; pathogen; programs; sex; sex determination; trait; vaccine trial; vector; vector control; vector mosquito

 DESCRIPTION (provided by applicant): Aedes aegypti is a major vector for dengue, yellow fever, and chikungunya viruses. The global incidence of dengue has increased dramatically in recent decades and nearly half of the world population is now at risk. No specific treatment for dengue exists and current prevention depends solely on effective vector control, which is hindered by increasing insecticide- resistance. Novel control strategies, informed by improved understanding of mosquito biology, are urgently needed. The long-term objective of this research is to decipher the mechanism of sex-determination in Ae. aegypti and translate such fundamental knowledge into safe and efficient methods to control mosquito-borne infectious diseases. Only female mosquitoes feed on blood and transmit pathogens. Thus maleness is the ultimate disease-refractory trait. Genetic evidence suggests that sex determination in aedine mosquitoes is governed by a dominant male-determining factor (M factor) that resides in the M-locus of a homomorphic sex- determining chromosome. Despite its importance as the master switch of sex-determination in many insects including mosquitoes, no M factor had been determined. Overcoming several technical bottlenecks, we have recently identified an M factor in Ae. aegypti we called Nix. Nix exhibits early embryonic expression and is the only gene that is persistently linked to the M- locus. We performed two complementary transient assays: Nix knockout with CRISPR/Cas9 resulted in largely feminized genetic males and the production of female isoforms of two key regulators of sexual differentiation; ectopic expression of Nix resulted in genetic females with nearly complete male genitalia. Thus, Nix is both required and sufficient to initiate male development. In this study, we will pursue the following specific aims: 1) Determine whether a Nix transgene is sufficient to convert females into fertile males and exploit Nix transgenics as a means for sex separation and population reduction of Ae. aegypti, 2) Elucidate the molecular mechanism underlying Nix function, and 3) Examine the species distribution, evolution, and functional conservation of Nix.

 描述（由申请人提供）：埃及伊蚊是登革热、黄热病和基孔肯雅病毒的主要传播媒介。近几十年来，全球登革热发病率急剧上升，目前世界上近一半的人口面临风险。目前尚无针对登革热的具体治疗方法，目前的预防仅依赖于有效的病媒控制，但杀虫剂抗药性的增加会阻碍这种控制。迫切需要通过加深对蚊子生物学的了解来制定新的控制策略。这项研究的长期目标是破译伊蚊的性别决定机制。埃及伊蚊，并将这些基础知识转化为控制蚊媒传染病的安全有效的方法。只有雌性蚊子以血液为食并传播病原体。因此，男性是最终的抗病性状。遗传证据表明，伊蚊的性别决定是由位于同态性别决定染色体的 M 位点上的显性雄性决定因子（M 因子）控制的。尽管M因子作为包括蚊子在内的许多昆虫性别决定的主开关很重要，但尚未确定M因子。克服了几个技术瓶颈，我们最近确定了 Ae 中的 M 因子。埃及伊蚊，我们称之为尼克斯。 Nix 表现出早期胚胎表达，并且是唯一与 M 基因座持续连锁的基因。我们进行了两项互补的瞬时测定：使用 CRISPR/Cas9 进行 Nix 敲除，导致基因男性很大程度上女性化，并产生性分化的两个关键调节因子的女性亚型； Nix 的异位表达导致遗传女性具有几乎完整的男性生殖器。因此，Nix 对于启动雄性发育来说既是必需的，也是充分的。在本研究中，我们将追求以下具体目标： 1) 确定 Nix 转基因是否足以将雌性转化为可育的雄性，并利用 Nix 转基因作为性别分离和减少伊蚊种群的手段。埃及伊蚊，2) 阐明 Nix 功能的分子机制，3) 检查 Nix 的物种分布、进化和功能保守。