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Free keywords:
biogeography; house mouse; intestinal microbiota; Mus musculus;
population structure
Abstract:
The microbial communities inhabiting the mammalian intestinal tract play an important
role in diverse aspects of host biology. However, little is known regarding the
forces shaping variation in these communities and their influence on host fitness. To
shed light on the contributions of host genetics, transmission and geography to diversity
in microbial communities between individuals, we performed a survey of intestinal
microbial communities in a panel of 121 house mice derived from eight locations
across Western Europe using pyrosequencing of the bacterial 16S rRNA gene. The host
factors studied included population structure estimated by microsatellite loci and mitochondrial
DNA, genetic distance and geography. To determine whether host tissue
(mucosa)-associated communities display properties distinct from those of the lumen,
both the caecal mucosa and contents were examined. We identified Bacteroides, Robinsoniella
and Helicobacter as the most abundant genera in both the caecal content and
mucosa-associated communities of wild house mice. Overall, we found geography to
be the most significant factor explaining patterns of diversity in the intestinal microbiota,
with a comparatively weaker influence of host population structure and genetic
distance. Furthermore, the influence of host genetic distance was limited to the mucosa
communities, consistent with this environment being more intimately coupled to the
host.
