Role of the microbiome of the schistosome snail host

项目摘要 微生物组-居住在人体和多种微生物中的微生物群落 其他动物门-越来越多地被认为在生物学的许多方面发挥着重要作用， 健康和疾病的关键决定因素。在无脊椎动物中，共生细菌参与合成 必需氨基酸或维生素，在消化纤维素，在保护免受寄生虫，在女性化， 单性生殖，甚至物种形成。在昆虫媒介中，有多种相互作用的实例， 常驻微生物组和寄生虫：白蛉肠道微生物组介导利什曼原虫传播， 沃尔巴克氏体细菌可以破坏蚊子中的疟疾传播，而两种reduviid细菌的微生物组 采采蝇介导锥虫感染。我们的目标是研究淡水蜗牛的微生物组 血吸虫病的媒介：六条证据表明微生物组在血吸虫病中可能发挥作用。 双脐螺-曼氏血吸虫相互作用：（i）蜗牛血淋巴（血液），到哪个孢子囊阶段 微生物体持续暴露，具有不同的微生物组，（ii）这种微生物组是分化的 从其他器官微生物组，并显示出最大的微生物多样性内蜗牛，（iii）不同的实验室 蜗牛种群具有独特的微生物组组成，（iv）不同蜗牛种群的共培养结果 在微生物组组成的快速变化中，（v）来自单一种群的蜗牛基因型具有抗性或 对细菌体感染敏感的微生物具有独特的微生物组，并且（vi）细菌体感染导致改变的 微生物组组成。在具体目标1中，我们将直接测试微生物组对蜗牛宿主的影响 发育和寄生虫易感性。这将通过生产无菌蜗牛来实现，就像 无菌小鼠已被用于了解微生物组在肥胖症中的直接作用。微生物组是 动态的，并且可能由于环境因素而在组成和丰度上变化。这些微生物群 修改甚至可以导致宿主的健康和适应性改变。具体目标2将侧重于 使用蜗牛的长期共培养（或共同花园）对蜗牛宿主适合度的微生物组修饰 携带独特微生物的种群。我们将使用下一代技术来表征采样的微生物组 16 S核糖体DNA的测序。该项目将（i）提供有关微生物组的基本信息 动力学和组成，（ii）确定微生物组在蜗牛-寄生虫相互作用中的作用， 蜗牛的繁殖力，以及（iii）具有揭示蜗牛-微生物-寄生虫相互作用新方面的强大潜力 可以通过新的干预措施来瞄准。

PROJECT SUMMARY The microbiome – the community of microorganisms that inhabit both the human body and that of multiple other animal phyla – is increasingly recognized to play an important role in many aspects of biology and as a key determinant of health and disease. In invertebrates, symbiotic bacteria are involved in synthesizing essential aminoacids or vitamins, in digesting cellulose, in protection against parasites, in feminization and parthenogenesis, and even in speciation. In insect vectors, there are multiple examples of interactions between resident microbiomes and parasites: the sandfly gut microbiome mediates Leishmania transmission, Wolbachia bacteria can disrupt malaria transmission in mosquitoes, while the microbiome of both reduviid bugs and tsetse flies mediates trypanosome infection. Our goal is to study the microbiome of the freshwater snail Biomphalaria, vector of schistosomiasis: six lines of evidence suggest a possible role for the microbiome in the Biomphalaria - Schistosoma mansoni interaction: (i) the snail hemolymph (blood), to which sporocyst stage schistosomes are continuously exposed, harbors a diverse microbiome, (ii) this microbiome is differentiated from other organ microbiomes and shows the greatest microbial diversity within snails, (iii) different laboratory snail populations have a distinctive microbiome composition, (iv) co-culture of different snail populations results in rapid change in microbiome composition, (v) snail genotypes from a single population that are resistant or sensitive to schistosome infection have distinctive microbiomes and (vi) schistosome infection results in altered microbiome composition. In specific aim 1 we will directly test the impact of microbiome on snail host development and schistosome parasite susceptibility. This will be done by generating germ-free snails, just as germ-free mice have been used to understand the direct role of the microbiome in obesity. Microbiomes are dynamic and may vary in composition and abundance due to environmental factors. These microbiome modifications can even lead to host health and fitness alterations. Specific aim 2 will focus on the impact of microbiome modification on snail host fitness using long term co-culture (or common garden) of snail populations carrying distinctive microbiomes. We will characterize sampled microbiomes using next generation sequencing of the 16S ribosomal DNA. This project will (i) provide fundamental information about microbiome dynamics and composition, (ii) determine the role of the microbiome in the snail-schistosome interactions and snail ftiness, and (iii) has strong potential to reveal new aspects of the snail-microbiome-parasite interaction that can be targeted by novel interventions.