DISSERTATION RESEARCH: Isolating a Mechanism for Microbial-Host Local Adaptation

这个项目研究外部环境如何塑造免疫系统。由于三个原因，海马为研究宿主与微生物的相互作用提供了理想的模型。它们免疫系统的遗传结构很简单。此外，它们的扩散能力有限，地理分布广泛。此前在新西兰和澳大利亚东南部对大腹海马进行的研究发现，基因组中与免疫反应相关的部分与未被选择的基因组部分的遗传多样性模式存在显著差异。这项提议旨在对寄主-微生物关联的现场观察进行实验测试。它将解决宿主-微生物共同进化理论中的一个关键问题：自然种群中的宿主-微生物联合是一种免疫的局部适应吗？海洋环境为食物、交通、商业和娱乐提供了重要的经济引擎，但我们仍然对人类活动如何影响生物和生态系统健康的了解很少。这项研究的结果将被纳入NSF资助的微生物学真实研究体验项目，该项目服务于纽约城市大学十个校区的学生，并将通过初级产业部、渔业服务商业渔业服务部和国家水和大气研究所为海洋保护规划和管理提供信息。宿主与微生物的相互作用是被低估的适应驱动因素。该项目将通过测试海洋物种腹海马体(盆腹海马体)中宿主-微生物协会的适合性结果，来评估主要组织相容性II类基因座(MHII)的潜在局部适应机制。先前对其地理范围内的野生腹肌的研究发现，相对于中性基因座，种群水平上的MHII变异性水平更高。对宿主肠道微生物群的测序表明，当地环境(城市、农业或原始)对从这些地点收集的宿主的微生物组成有显著影响。实验种群将暴露在与自然种群中宿主呈正、负或中性关联的微生物中，并将测量mhii基因对生长、条件、免疫反应和生存的影响。这里提出的这项研究是一个令人兴奋的机会，可以明确测试宿主-微生物联合的现场观察，并针对一个关键的进化概念，即微生物介导的局部适应，使用反映微生物暴露的自然途径的实验方案。

This project investigates how the external environment shapes the immune system. Seahorses provide an ideal model for studying host-microbe interactions for three reasons. The genetic structure of their immune system is simple. Also, their dispersal capability is limited, and their geographic distribution is broad. Previous research on the pot-bellied seahorse across its range in New Zealand and southeastern Australia found striking differences between the pattern of genetic diversity in those parts of the genome related to immune response versus those parts of the genome that are not under selection. This proposal aims to experimentally test field observations of host-microbe associations. It will address a key question in host-microbial co-evolutionary theory: Are host-microbe associations in natural populations a type of local adaptation for immunity? Marine environments provide an essential economic engine for food, transportation, commerce and recreation, but we still have a poor understanding of how human activities impact resident organisms and influence ecosystem health. The results of this research will be incorporated into the NSF-funded Authentic Research Experience in Microbiology program serving students at ten City University of New York campuses, and will inform marine conservation planning and management through the Ministry of Primary Industries, FishServe Commercial Fisheries Services, and the National Institute of Water and Atmospheric Research.Host-microbe interactions are an underappreciated driver of adaptation. This project will evaluate a potential mechanism of local adaptation at the major histocompatibility class II locus (MHII) by testing the fitness consequences of host-microbe associations in the marine species Hippocampus abdominalis (the pot-bellied seahorse). Previous research on wild H. abdominalis across its geographic range detected enhanced levels of MHII variability at the population level relative to neutral loci. Sequencing of the host gut microbiome indicates that the local environment (urban, agricultural, or pristine) has a significant effect on the microbial composition of hosts collected from these sites. Experimental populations of H. abdominalis will be exposed to microbes showing positive, negative, or neutral associations with hosts in natural populations, and effects of MHII genotype on growth, condition, immune response and survival will be measured. The research proposed here represents an exciting opportunity to explicitly test field observations of host-microbe associations and targets a key evolutionary concept, microbe-mediated local adaptation, using an experimental protocol reflecting natural pathways of microbial exposure