Illumination of behavior leading to host exploitation by a context-dependent mutualist

阐明导致宿主利用环境依赖的互利共生者的行为

• 批准号: 2127521
• 负责人: Rachelle M Adams
• 金额: $ 52.19万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-15 至 2025-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2127521&HistoricalAwards=false
• 关键词: Illumination; behavior; leading; host; exploitation

Parasitic lifestyles are more common than all other lifestyles combined and host-parasite interactions shape food webs, influence behavior, and alter population size and structure. Because insects are widespread, hyper-diverse, and abundant, and most are parasitic, they are ideal subjects for species interaction studies. The proposed study leverages a unique parasite system—easily studied in the field and manipulated in the lab—to address key questions about species interactions. The research objective is to identify behaviors that lead to obligate symbioses (different species living together), while taking into consideration a network of interacting entities (ants, fungus, and bacteria). This comprehensive study is original in its scope, spanning temporal and biological scales, but is also creative in the use of integrative methods (population genetics, morphology, chemical ecology, behavior) to better understand symbiotic relationships. The charismatic Megalomyrmex guest ant/fungus-farming ant host/parasite system has the potential to reshape the way symbioses are perceived while providing a new model that will serve the needs of students and researchers now and in the future. Additionally, these efforts will include students in research and create a bilingual online badge-based educational summer program, led by diverse role models, and centered on conservation of symbioses, enhancing accessibility to STEM education.This study will enable much-needed crosstalk among the fields of parasitology and sociobiology. Megalomyrmex symmetochus is an obligate ‘guest ant’ parasite of a fungus-farming ant, Sericomyrmex amabilis. The costs of hosting guest ants can quickly shift to a net benefit when a more lethal parasite threatens hosts, because the guest ants offer protection through their alkaloidal venom weaponry. Integrative approaches in animal behavior, following a parasitological exploitation framework, will clarify how these context-dependent mutualists influence symbiotic networks. Aims are organized by the stages leading to exploitation, from the initiation of an obligate symbiotic interaction (host-finding/dispersal) (Aim I) to colony integration and species network maintenance (Aims II and III). Aim I compares dispersal ability and population dynamics of hosts and their parasites, capitalizing on flight morphology and population genomics methods. Host-finding strategies will be identified for the first time in a social parasite (one social organism parasitizing another) using a reductionist approach. Not only will ant and fungus garden volatiles be characterized but compounds that attract the host and parasite ants will be discovered. Aims II and III center on parasite venom function. Toxicity and behavioral assays will test if parasitized and non-parasitized ant colonies differ physiologically and behaviorally when exposed to parasite-derived venom alkaloids. 16S metagenomics, culture-based assays, and manipulation experiments will distinguish bacterial symbionts and determine which are susceptible to antimicrobial alkaloidal venom. This work fills a significant gap by identifying how social parasites solve the challenges all parasites face to achieve successful exploitation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

寄生虫的生活方式比所有其他生活方式结合起来更常见，宿主-寄生虫相互作用形成食物网，影响行为，改变种群规模和结构。由于昆虫分布广泛，多样性高，数量丰富，大多数是寄生虫，它们是物种相互作用研究的理想对象。这项研究利用了一个独特的寄生虫系统，很容易在现场研究和在实验室操作，以解决有关物种相互作用的关键问题。研究目标是确定导致专性共生（不同物种生活在一起）的行为，同时考虑相互作用的实体（蚂蚁，真菌和细菌）的网络。这项综合研究在其范围内是原创的，跨越时间和生物尺度，但在使用综合方法（种群遗传学，形态学，化学生态学，行为）以更好地理解共生关系方面也具有创造性。极具魅力的Megalomyrmex客蚁/真菌养殖蚂蚁宿主/寄生虫系统有可能重塑共生的感知方式，同时提供一个新的模式，将服务于学生和研究人员的需求，现在和未来。此外，这些努力将包括学生在研究和创建一个双语在线徽章为基础的教育暑期课程，由不同的榜样领导，并以共生保护为中心，提高STEM教育的可及性。这项研究将使寄生虫学和社会生物学领域之间急需的串扰。Megalomyrmex symmetochus是一种专性的“客人蚂蚁”寄生的真菌养殖蚂蚁，Sericomyrmex amabilis。当更致命的寄生虫威胁宿主时，招待客人蚂蚁的成本可以迅速转变为净收益，因为客人蚂蚁通过它们的毒液武器提供保护。在动物行为的综合方法，以下寄生虫学开发框架，将澄清这些上下文相关的互利主义者如何影响共生网络。目的是组织的阶段导致开发，从一个专性的共生相互作用（主机发现/传播）（目的I）的殖民地整合和物种网络维护（目的II和III）的启动。目的利用飞行形态学和种群基因组学方法，比较寄主和寄生虫的扩散能力和种群动态。宿主发现策略将首次在社会寄生虫（一个社会有机体寄生另一个）中使用简化的方法进行识别。不仅将蚂蚁和真菌花园挥发物的特点，但吸引主机和寄生蚂蚁的化合物将被发现。目的II和III以寄生虫毒液功能为中心。毒性和行为测定将测试寄生和非寄生蚁群在暴露于寄生虫衍生的毒液生物碱时是否在生理和行为上不同。16 S宏基因组学，基于培养的测定和操作实验将区分细菌共生体，并确定哪些对抗菌性毒液敏感。这项工作通过确定社会寄生虫如何解决所有寄生虫面临的挑战以实现成功利用，填补了一个重大空白。该奖项反映了NSF的法定使命，并且通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持审查标准。