Variance in the Gut microbiota of Wild Rodent along the Spatial Distance
and Species Identity Scale
Abstract
1. The gut microbiota of rodents is essential for survival and
adaptation, and has been shown to be susceptible to a variety of
factors, ranging from environmental conditions to genetic
predispositions. Nevertheless, few comparative studies have considered
the contribution of species identity and geographic spatial distance to
the variation in gut microbiota. 2. Here, we investigated the gut
microbial communities of four wild rodent species (Rattus norvegicus,
Apodemus agrarius, Cricetulus barabensis, and Tscherskia triton) at five
sites in northern China’s farming-pastoral transition zone. By
performing a cross-factorial comparison, we are able to test whether
belonging to the same species, or instead, being in the same capture
site dominates in determining gut microbiota composition. 3. Our
analysis found that the Amplicon Sequence Variants (ASVs) showed a
partial overlap with the species identity and the geographic capture
sites, which did not reveal a ‘phylosymbiosis’ pattern. 4. The gut
microbiota of these four rodent species adhered to typical mammalian
characteristics, predominantly characterised by the Firmicutes and
Bacteroidetes phyla. As the geographic distance between populations
increased, the shared microbial taxa among conspecific populations
decreased. We observed that within a relatively small geographical
range, even different species exhibit convergent α-diversity due to
their inhabitation within the same environmental microbial pool. In
contrast, the composition and structure of the intestinal microbiota in
allopatric populations of A. agrarius showed marked differences, as well
as C. barabensis. Additionally, geographical environmental elements,
exhibited significant correlations with diversity indices. Conversely,
host-related factors had minimal influence on microbial abundance. 5.
These findings illuminated that the similarity of the microbial
compositions was not determined primarily by the host species, the
location of the sampling explained a greater amount of variation in the
microbial composition, indicating that the local environment played a
crucial role in shaping the microbial composition.