Collaborative Research: The genetic basis, biosynthetic pathways and evolution of chemical defense in carabid beetles

合作研究：步甲的遗传基础、生物合成途径和化学防御进化

• 批准号: 1556957
• 负责人: Kipling Will
• 金额: $ 49.71万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1556957&HistoricalAwards=false
• 关键词: Collaborative; Research; genetic; basis; biosynthetic

The main goal of this project is to understand, at the molecular level, one of the most remarkable chemical defense systems found in nature - the explosive, extremely hot spray of the bombardier beetles. Insects make up much of the animal life that has evolved on Earth. Understanding why there are so many different kinds of insects and why they are so successful is fundamental to understanding how the wide diversity of life evolved. Insects are well known for producing many different chemical compounds that are required for their communication. Some chemicals help them to locate mates and food resources, others help them to organize activities within the nest or hive, and many others are used to warn off and defend against predators. This project focuses on this last aspect and is specifically testing the idea that the genes responsible for production of the hot chemical spray of the bombardier beetles are closely related to the genes responsible for producing similar chemicals in the insect's outer shell or exoskeleton. A main strength of the project is that it tackles this question by using multiple complementary approaches and by comparing eight different beetle species that are related to varying degrees. Half of these species have evolved a chemical defense system, the other half have not evolved this ability. Many college students and young scientists will receive scientific training in conjunction with the project. People of all ages are highly captivated by these beetles, particularly school age children. With the bombardier beetle as a model, the project will help develop elementary school level hands-on activities and lesson plans on topics in chemical ecology and biological chemical defense evolution that will reinforce the Next Generation Science.Ground beetles and their relatives form the largest clade of organisms that use a single homologous gland system to produce no less than 19 distinct classes of chemical compounds for defense. This project will develop a detailed functional and evolutionary understanding of defensive chemistry evolution by focusing on species from the four lineages of quinone producing carabid beetles, including species commonly known as the bombardier beetles, which chemically blast their defensive quinones at extremely hot temperatures (up to 100 °C). Using a multidisciplinary approach, this project will identify genes involved in quinone production, elucidate chemical biosynthetic pathways, and describe the genetic architecture of quinone evolution. From gland-specific transcripts, candidate genes related to the production of defensive secretions will be identified and gene function will be validated experimentally by blocking gene transcription and looking at phenotypic changes in the compounds produced. The researchers will test the hypothesis that the genes up-regulated in secretory cells during quinone synthesis are closely related to those involved in quinone production in arthropod cuticle. Thus the project will empirically address the well-known, but untested, scenario of how the bombardier beetle evolved its explosive defense abilities. Ultimately, this project will explore how genetics and chemistry can interact over time and will reveal insights into the fundamental process of evolution.

该项目的主要目的是在分子水平上了解自然界中最引人注目的化学防御系统之一 - 爆炸性甲虫的爆炸性，极热的喷雾剂。昆虫构成了在地球上进化的动物生命。了解为什么有这么多不同的绝缘材料以及为什么它们如此成功对于了解生活的广泛多样性如何发展至关重要。昆虫以产生许多不同的化合物而闻名。有些化学物质帮助他们找到伴侣和食物资源，另一些化学物质帮助他们在巢或蜂巢中组织活动，而许多其他化学物质被用来警告和防御掠食者。该项目的重点是最后一个方面，并专门测试了负责产生孟买甲虫热化学喷雾剂的基因与负责在昆虫外壳或外骨骼中产生相似化学物质的基因密切相关。该项目的一个主要优势是，它通过使用多种互补方法并比较八种与不同程度相关的甲壳虫物种来解决这个问题。这些物种中有一半已经发展出一种化学防御系统，另一半没有发展出这种能力。许多大学生和年轻科学家将与该项目一起接受科学培训。各个年龄段的人都被这些甲虫，尤其是学龄儿童所吸引。该项目以轰炸甲虫为模型，将有助于开发小学水平的动手活动和有关化学生态学和生物学化学防御进化主题的课程计划，这些计划将增强下一代科学。地面甲虫及其亲属构成了最大的生物体，是使用单个同源腺体系统生产出19种不同化学化学的单个同源腺体的生物体。该项目将通过重点关注产生奎因酮甲虫的四个谱系的物种来发展对防御化学演化的详细功能和进化理解，其中包括通常被称为孟买甲虫的物种，在极度热的温度（最高100°C）上，该物种在化学上爆炸了其防御性奎因酮。使用多学科方法，该项目将确定涉及奎因酮生产，阐明化学生物合成途径的基因，并描述喹酮进化的遗传结构。从特异性的转录本中，将确定与防御分泌物的产生有关的候选基因，并通过阻断基因转录并查看产生的化合物的表型变化来实验验证基因功能。研究人员将检验以下假设：喹酮合成过程中秘密细胞中上调的基因与参与节肢动物角质层中喹酮产生的基因密切相关。该项目将紧急解决孟迪甲甲虫如何发展其爆炸性防御能力的知名但未测试的方案。最终，该项目将探讨遗传学和化学如何随着时间的推移相互作用，并揭示对进化基本过程的见解。