共生微生物对蚂蚁植食性进化的影响

共生微生物是真核生物进化及多样性形成的主要推动力，其对动物的植食性进化的影响是当前的研究热点之一。由于植物来源食物中氮元素匮乏，人们提出了共生微生物能够帮助动物克服这些营养屏障为其开拓植食性生态位的假说。然而，由于从肉食性向植食性转变的过程很难在可观测的时间尺度上发生，致使该假说缺乏直接的实验证据。因此，亟需建立一个模式研究系统，来探讨共生微生物在动物食性转变初期以及稳定占据植食性生态位这两个阶段所起的作用。本项目计划以蚂蚁作为研究模型，分析共生微生物在入侵蚂蚁食性转变初期所起的作用，探究植食性蚂蚁是否具有稳定特异的共生微生物群落，并解析共生微生物弥补宿主食物中缺乏的氮元素的作用机制，全面研究共生微生物对蚂蚁植食性进化的影响，加强理解互惠共生关系如何影响蚂蚁多样性的形成和维持。

Microbial symbiosis is the major driving force behind evolution and diversification of eukaryotes. Its role in the evolution of herbivory in animals is currently one of the research hotspots in this field. Due to nitrogen deficiency in plant derived diets, it has been proposed that animals depend on symbiotic microbes to overcome nutrient limitation and explore a plant dietary niche. However, since it is not possible to observe the trophic transition from carnivory to herbivory over a short time scale, there are still no direct evidence to support the contribution of symbiotic microbes in the evolution of animal herbivory. Therefore, it is important to construct a model system to study the role of symbiotic microbes in the early stages of trophic shifts and in the later stages of stable occupation of plant dietary niches. This project aims to test the hypothesis using ants as a study model. We will investigate the contribution of symbiotic microbes in the early stage of trophic shift of invasive ant species. We will further examine whether herbivorous ants harbor stable and host-specific microbiota and address the mechanism behind nitrogen supplementation by symbiotic microbes for herbivorous ant hosts. This study will provide hard evidence on the role of symbiotic microbes in the evolution of ant herbivory and will provide valuable insights on the role of mutualistic interactions in origin and maintenance of ant biodiversity.