Molecular Genetic and Functional Analysis of Chitin Synthase During Insect Development

昆虫通过将自己包裹在几丁质角质层中，并在肠道内内衬由几丁质和蛋白质组成的营养基质（PM）来保护自己免受机械伤害和捕食者的伤害。几丁质合成酶（甲壳素合成酶，CHS）是由多个基因和交替外显子剪接产生的。本研究将确定这些CHS异构体在角质层和PM合成中的作用。红粉甲虫（Tribolium castaneum）将用于在整个昆虫水平上研究如何协调和调节CHS基因的活动以确保昆虫的正常发育。为了了解每种CHS在胚胎、幼虫和成虫角质层和PM中的作用，研究人员将使用每种基因特异性的干扰rna灭活整个昆虫的每个基因，并确定昆虫发育各个阶段对角质层和PM完整性的影响。在分子水平上，研究人员将大量生产每种CHS或其催化结构域，并确定其生化特性，包括对各种几丁质抑制剂的敏感性。在Tribolium项目中产生的知识将使我们对几丁质代谢及其对昆虫发育的影响有更广泛的了解。CHS是一些杀虫剂的靶蛋白，本研究结果将为设计控制农业害虫和病媒的其他战略提供有用的信息，同时尽量减少对环境的有害影响。这笔奖金还将帮助研究人员持续努力维护受欢迎的网站Tribolium Genetics website；回应有关Tribolium库存、信息和建议的请求；并开展涉及K-12学生和生物教师的外展活动。

Insects protect themselves from mechanical injury and predators by enveloping themselves in a chitinous cuticle and lining their guts with a peritrophic matrix (PM) made up of chitin and protein. Several isoforms of the enzyme that makes chitin, chitin synthase (CHS), are generated by multiple genes and alternate exon splicing. This study will determine the role of these CHS isoforms in the synthesis of the cuticle and the PM. The red flour beetle, Tribolium castaneum, will be used to examine at the whole insect level how the activities of CHS genes are coordinated and regulated to ensure proper insect development. To understand the role of each CHS in embryonic, larval and adult cuticle and PM, the investigators will inactivate each gene in whole insects using interfering RNAs specific for each gene and determine the effects on cuticle and PM integrity at each stage of insect development. At the molecular level, the investigators will produce large amounts of each CHS or their catalytic domains and determine their biochemical properties including susceptibility to various chitin inhibitors. Knowledge generated in this proposal with Tribolium will lead to greater general understanding of chitin metabolism and its influence on insect development. CHS is the target protein of some insecticides and the results of this study will provide useful information for the design of additional strategies to control insect pests in agriculture and disease vectors, while minimizing detrimental effects on the environment. This award will also assist ongoing efforts by the investigators to maintain the popular website, Tribolium Genetics Website; to respond to requests for Tribolium stocks, information and advice; and to conduct outreach activities involving K-12 students and biology teachers.