Microbiome and climate: Skin microbial diversity and community functions of Polypedates megacephalus (Anura: Rhacophoridae) associated with bioclimate

The microbiome inhabiting animal skin plays a crucial role in host fitness by influencing both the composition and function of microbial communities. Environmental factors, including climate, significantly impact microbial diversity and the functional attributes of these communities. However, it remains unclear how specific climatic factors affect amphibian skin microbial composition, community function, and the relationship between these two aspects. Given that amphibians are poikilotherms, and thus more susceptible to temperature fluctuations, understanding these effects is particularly important. Here, we investigated the skin microbiome of the rhacophorid tree frog Polypedates megacephalus across different climatic regimes using 16S rRNA gene sequencing. Skin swab samples were collected from nine populations of P. megacephalus adults in the Guangxi region, China. The majority of the core microbiota were found to belong to the genus Pseudomonas. Our findings indicate that microbial community diversity, composition, and function are associated with changes in climatic conditions. Specifically, the taxonomic and functional diversity of the skin microbiome increased in response to greater climate variability, particularly in temperature fluctuations. Additionally, the functional attributes of microbial communities changed in parallel with shifts in community diversity and composition, suggesting that environmental filtering driven by climate changes negatively impacts microbial community functional redundancy. These results highlight the critical influence of climatic factors on amphibian skin microbiomes and offer new insights into how microbial composition and function contribute to host adaptation in varying environmental conditions.