Cloacal microbiota are biogeographically structured in larks from desert, tropical and temperate areas

BMC Microbiology

article

van Veelen, H. Pieter J.¹  Ibáñez-Álamo, Juan Diego¹  Horrocks, Nicholas P. C.¹  Hegemann, Arne¹  Ndithia, Henry K.¹  Shobrak, Mohammed⁷  Tieleman, B. Irene¹ 

[1] Groningen Institute for Evolutionary Life Sciences, University of Groningen;Wetsus, European Centre of Excellence for Sustainable Water Technology;Department of Zoology, Faculty of Sciences, University of Granada;Cambridge Institute of Therapeutic Immunology & Infectious Disease ,(CITIID), Cambridge Biomedical Campus, University of Cambridge;Department of Biology, Lund University;Ornithology Section, Department of Zoology, National Museums of Kenya;Biology Department, Science College, Taif University;National Centre for Wildlife

关键词: Alaudidae;    Avian microbiota;    Cloacal microbiota;    Host-microbiome;    Microbial biogeography;   

DOI  :  10.1186/s12866-023-02768-2

学科分类：放射科、核医学、医学影像

来源: BioMed Central

【 摘 要 】

In contrast with macroorganisms, that show well-documented biogeographical patterns in distribution associated with local adaptation of physiology, behavior and life history, strong biogeographical patterns have not been found for microorganisms, raising questions about what determines their biogeography. Thus far, large-scale biogeographical studies have focused on free-living microbes, paying little attention to host-associated microbes, which play essential roles in physiology, behavior and life history of their hosts. Investigating cloacal gut microbiota of closely-related, ecologically similar free-living songbird species (Alaudidae, larks) inhabiting desert, temperate and tropical regions, we explored influences of geographical location and host species on α-diversity, co-occurrence of amplicon sequence variants (ASVs) and genera, differentially abundant and dominant bacterial taxa, and community composition. We also investigated how geographical distance explained differences in gut microbial community composition among larks. Geographic location did not explain variation in richness and Shannon diversity of cloacal microbiota in larks. Out of 3798 ASVs and 799 bacterial genera identified, 17 ASVs (< 0.5%) and 43 genera (5%) were shared by larks from all locations. Desert larks held fewer unique ASVs (25%) than temperate zone (31%) and tropical larks (34%). Five out of 33 detected bacterial phyla dominated lark cloacal gut microbiomes. In tropical larks three bacterial classes were overrepresented. Highlighting the distinctiveness of desert lark microbiota, the relative abundances of 52 ASVs differed among locations, which classified within three dominant and 11 low-abundance phyla. Clear and significant phylogenetic clustering in cloacal microbiota community composition (unweighted UniFrac) showed segregation with geography and host species, where microbiota of desert larks were distinct from those of tropical and temperate regions. Geographic distance was nonlinearly associated with pairwise unweighted UniFrac distances. We conclude that host-associated microbiota are geographically structured in a group of widespread but closely-related bird species, following large-scale macro-ecological patterns and contrasting with previous findings for free-living microbes. Future work should further explore if and to what extent geographic variation in host-associated microbiota can be explained as result of co-evolution between gut microbes and host adaptive traits, and if and how acquisition from the environmental pool of bacteria contributes to explaining host-associated communities.

【 授权许可】

CC BY|CC0