Seasonal cycle patterns of gut viruses and bacteria in two high-altitude model animals (Ochotona Curzniae, Myospalax baileyi) over a period of 2.5 years
Gut microbes significantly contribute to the animal's adaptation to seasons. Previous studies focused on seasonal cyclic patterns of gut bacteria in humans and plain animals, and fewer studies have explored intestinal viruses of wild animals from extreme plateau environment. Here, we tracked plateau pikas (Ochotona Curzniae, PP) and plateau zokor (Myospalax baileyi, PZ) on the Qinghai-Tibet Plateau over 2.5 years spanning multiple seasons through metagenomic and amplicon data. We found that the intestinal viral diversity in the PP that prefer to active on the ground exhibited a cyclical pattern with the seasons, with significantly higher diversity in the warm season compared to the cold season, while no such variation was observed in PZ that live underground. The assembly process of the PP intestinal virus community was primarily stochastic, while PZ was mainly deterministic process. In degrading recalcitrant polysaccharides, it mainly relied on bacterial communities, while viruses assisted bacterial communities. Intestinal viruses were enriched with a small number of genes to degrade recalcitrant polysaccharides, only including oligosaccharides and hemicellulose. While bacterial communities were enriched with more genes to degrade recalcitrant polysaccharides, including cellulose, hemicellulose, chitin and starch. The co-occurrence networks showed more viruses and bacteria in a mutually beneficial symbiotic relationship during the warm season. Our study contributes to the understanding of the seasonal and diet adaptability of gut viruses in plateau wildlife.