巢湖野鸟与同域禽类肠道真菌群落结构特征

Characteristics of fungal community structures in guts of wild birds and sympatric poultry in Chaohu Lake

摘要:

目的 鸟类具有独特的生活史特征，是研究肠道微生物的理想模型。野鸟与家禽生态位重叠，增加了病原菌交互传播的风险。本研究重点关注巢湖野鸟(八哥、小天鹅、白骨顶鸡)与同域家禽(家鸭和家鸡)肠道真菌及病原菌的群落特征。方法 采用高通量测序技术(Illumina MiSeq)对中国巢湖流域野鸟及同域家禽肠道真菌群落进行分析，并着重关注各物种肠道病原菌的特征。结果 家鸭与白骨顶鸡肠道真菌多样性显著高于家鸡、八哥和小天鹅。不同物种肠道真菌群落组成存在显著差异。家禽因投喂谷物饲料，其肠道中显著富集子囊菌门(Ascomycota)、被孢霉门(Mortierellomycota)及哈萨克斯坦酵母属(Kazachstania)等与谷物降解相关的真菌类群。小天鹅作为植食性水鸟，其肠道中高效降解植物的真菌枝孢霉属(Cladosporium)在群落中占据主导地位，维持了很高的腐生真菌相对丰度。与家禽相比，野鸟肠道真菌群落构建以确定性过程为主导，表明野鸟具有更强的肠道过滤能力。此外，野鸟携带的病原菌多样性与相对丰度更低。结论 野鸟和家禽肠道真菌群落特征呈现出显著的宿主特异性。家禽因投喂谷物饲料，其肠道中显著富集与谷物降解相关的真菌类群。野鸟肠道呈现更强的过滤能力，降低了病原真菌的多样性与相对丰度。

Abstract:

Objective Birds, with unique life history characteristics, are ideal models for studying gut microorganisms. The niche overlap between wild birds and poultry increased the risk of interactive transmission of pathogens. This study focused on the community characteristics of gut fungi and pathogens in wild birds (crested myna, tundra swan, and common coot) and sympatric poultry (domestic duck and domestic chicken) in Chaohu Lake.Methods High-throughput sequencing (Illumina MiSeq) was employed to analyze the fungal communities in guts of wild birds and sympatric poultry in Chaohu Lake of China, and the characteristics of gut pathogens of each species were particularly studied.Results The gut fungal diversity of domestic duck and common coot was significantly higher than that of domestic chicken, crested myna, and tundra swan. There were significant differences in gut fungal community composition among different species. Due to grain-based diets, the guts of poultry were significantly enriched with the fungal taxa related to grain degradation, such as Ascomycota, Mortierellomycota, and Kazachstania. Tundra swan is herbivorous waterfowl. The genus Cladosporium, efficient plant-degrading fungi, dominated in the gut of tundra swan. The gut of tundra swan maintained higher relative abundance of plant saprotroph. The fungal community assembly in guts of wild birds was dominated by deterministic processes, which indicated that wild birds had a stronger gut filtering capacity. In addition, wild birds had lower diversity and relative abundance of pathogens.Conclusion The characteristics of gut fungal communities in wild birds and domestic poultry showed significant host specificity. Due to grain-based diets, the guts of poultry were significantly enriched with fungal groups related to grain degradation. The guts of wild birds had a stronger filtering capacity, which reduced the diversity and relative abundance of pathogens.