Biocomplexity in the Environment/GEN-EN: Response of Host and Symbiont Genomes to Environmental Stress and its Ecological Consequences

博士们已获得一笔赠款。亚利桑那大学的南希·莫兰和卡特里娜·曼金，以及威斯康星大学的安东尼·艾夫斯博士，在分子和生态水平上探讨共生感染在决定昆虫对热应激的耐受性方面的作用。将确定蚜虫兼性细菌内共生体的完整基因组序列。利用这些和其他基因组数据的方法将被使用，包括测量宿主和共生体在不同热环境下热应激基因的表达。这些研究将揭示宿主之间的共生分布以及应激反应的遗传变异如何影响热敏性。此外，将在野外环境下审查热耐受性变化的生态后果；这些实验将揭示耐热性如何与其他生物因素（如捕食者和寄生虫）相互作用，以确定种群密度和持久性。慢性感染是大多数动物（包括人类和昆虫）生命周期的正常部分，但尚不清楚这种感染如何影响对不断变化的环境条件的耐受性。同时，维持共生关系的力量依赖于遗传和环境因素的共同作用，但没有研究将这些因素放在一起。在这个项目中，具有生态学和分子生物学专业知识的研究人员将应用这两个领域的方法来获得这些问题的答案。通过阐明热量影响动物种群的分子和生态机制，这些发现将展示单个物种的地理范围和丰度是如何受到气候变化的影响的。研究结果将与农业害虫和病媒昆虫特别相关，其中很大一部分昆虫与蚜虫具有类似的共生关系。此外，一项实质性的教育计划将向亚利桑那州的中学教师介绍使用最先进的分子工具来分析生物体如何与环境压力相互作用。

A grant has been awarded to Drs. Nancy Moran and Katrina Mangin of the University of Arizona, and Dr. Anthony Ives of the University of Wisconsin to address the role of symbiotic infections in determining tolerance of insects to heat stress, both at the molecular and ecological levels. The complete genome sequence of a facultative bacterial endosymbiont of aphids will be determined. Approaches exploiting this and other genomic data will be used, including measures of expression of heat stress genes of both hosts and symbionts under different thermal environments. These studies will reveal how heat sensitivity is affected by symbiont distributions among hosts as well as by genetic variation in stress responses. In addition, the ecological consequences of variation in thermal tolerances will be examined under field environments; these experiments will reveal how heat tolerance interacts with additional biological factors, such as predators and parasites, to determine population density and persistence. Chronic infection is a normal part of the life cycle for most animals, including humans and insects, but it is not known how such infection affects tolerance to changing environmental conditions. At the same time, the forces that maintain symbiotic associations are dependent on the joint effects of genetic and environmental factors, but no studies have addressed these together. In this project, researchers with expertise in both ecology and molecular biology will apply methodologies from both fields to obtain answers to these issues. By illuminating the molecular and ecological mechanisms through which heat affects animal populations, the findings will demonstrate how geographic ranges and abundances of individual species are impacted by changes in climate over time. Results will be particularly relevant to insects that are agricultural pests and vectors of disease, a large proportion of which have symbiotic associations similar to those of aphids. In addition, a substantial educational program will introduce Arizona secondary school teachers to the use of state-of-the-art molecular tools for analyzing how organisms interact with environmental stress.