CAREER: Fungal pathogen induced dysbiosis alters microbiome assembly along host resource gradients: implications for biodiversity conservation

爬行动物是地球上最受威胁的物种之一，约有20%的物种面临灭绝的危险。这种威胁可能是环境、气候和生物因素（如新出现的病原体）的累积效应。最近，蛇的真菌病原体（Ophidiomyces ophidiicola）与美国的人口下降有关。这种蛇皮病原体通过影响细菌组合的结构和功能来引起皮肤微生物组的变化。微生物组是宿主健康的重要组成部分，可以提供对野生动物病原体的抗病性。本研究将研究O. Ophidiicola和皮肤微生物组，具有切实的保护意义。所提出的模型系统将促进对有助于跨梯度微生物群落变化的机制的理解。研究人员建议通过测试真菌病原体对微生物群落组装机制的影响来填补知识空白，更广泛地说，推进疾病生态学的基础知识。与动物园和大烟山国家公园的外联活动将有助于向公众宣传野生动物疾病和皮肤微生物组在生物多样性保护中的重要性。中田纳西州立大学的一个本科生微生物组科学家项目将有助于培养下一代微生物生态学家。 生态失调被定义为对微生物组的典型功能或组成的破坏，可能对宿主健康产生不利影响。拟议的工作将使用蛇真菌疾病系统来提高对疾病生态学，细菌-真菌相互作用和皮肤微生物群落生态失调的理解。这将通过生态学中跨多个尺度（现场，活体动物，实验室）的研究来实现，以允许明确的假设检验，观察到的生态趋势的交叉验证和建立管理病原体诱导的生态失调的基本规则。研究人员将测试以下假设，H1：爬行动物皮肤微生物组的细菌组合是通过与真菌在空间，时间和宿主生态中的相互作用而构建的。H2：微生物组α-和β-多样性的变化可预测地被病原体诱导的生态失调所改变。H3：分类学和功能变异性归因于宿主资源和/或真菌代谢物梯度的代谢生态位效应。该研究将对爬行动物物种的细菌和真菌微生物组多样性进行全面普查，为专注于微生物相互作用和疾病生态学的实验系统提供重要贡献。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Reptiles are among the most threatened species on Earth with approximately 20% of taxa at risk of extinction. This threat is likely a cumulative effect of environmental, climatic, and biotic factors, such as emerging pathogens. Recently, a fungal pathogen of snakes (Ophidiomyces ophidiicola) has been linked with population declines in the USA. This snake skin pathogen causes changes to the skin microbiome by affecting the structure and function of bacterial assemblages. The microbiome is an important component of host health and can provide disease resistance to wildlife pathogens. This research will study interactions between O. ophidiicola and skin microbiomes, with tangible conservation implications. The proposed model system will advance understanding of mechanisms that contribute to variation in microbiome communities across gradients. The researchers propose to fill a knowledge gap by testing for the effects of fungal pathogens on mechanisms of microbiome community assembly, and more generally, advance fundamental knowledge of disease ecology. Outreach activities with zoos and the Great Smoky Mountains National Park will help inform the general public about wildlife disease and the importance of skin microbiomes in biodiversity conservation. An undergraduate microbiome scientist program at Middle Tennessee State University will contribute to the training of the next generation of microbial ecologists. Dysbiosis is defined as disruption to the typical function or composition of a microbiome, potentially resulting in adverse effects to host health. The proposed work will use the snake fungal disease system to improve understanding of disease ecology, bacterial-fungal interactions and dysbiosis to skin microbiomes. This will be accomplished by studies spanning multiple scales (field, live animal, lab-based) in ecology to allow for explicit hypothesis tests, cross validation of observed ecological trends and establishment of fundamental rules governing pathogen induced dysbiosis. The researchers will test the following hypotheses, H1: Bacterial assemblages of reptile skin microbiomes are structured by interactions with fungi across space, time and host ecology. H2: Variation in microbiome α- and β-diversity are predictably altered by pathogen induced dysbiosis. H3: Taxonomic and functional variability are attributed to metabolic niche effects across a gradient of host resources and/or fungal metabolites. This research will produce a comprehensive census of bacterial and fungal microbiome diversity on reptile species with important contributions to inform experimental systems focused on microbial interactions and disease ecology.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.