Wanelik Klara M, Raulo Aura, Troitsky Tanya, Husby Arild, Knowles Sarah C L
Department of Biology, University of Oxford, Oxford, UK.
Department of Computing, University of Turku, Turku, Finland.
Anim Microbiome. 2023 May 31;5(1):29. doi: 10.1186/s42523-023-00247-7.
The mammalian gut microbiota influences a wide array of phenotypes which are relevant to fitness, yet knowledge about the transmission routes by which gut microbes colonise hosts in natural populations remains limited. Here, we use an intensively studied wild population of wood mice (Apodemus sylvaticus) to examine how vertical (maternal) and horizontal (social) transmission routes influence gut microbiota composition throughout life.
We identify independent signals of maternal transmission (sharing of taxa between a mother and her offspring) and social transmission (sharing of taxa predicted by the social network), whose relative magnitudes shift as hosts age. In early life, gut microbiota composition is predicted by both maternal and social relationships, but by adulthood the impact of maternal transmission becomes undetectable, leaving only a signal of social transmission. By exploring which taxa drive the maternal transmission signal, we identify a candidate maternally-transmitted bacterial family in wood mice, the Muribaculaceae.
Overall, our findings point to an ontogenetically shifting transmission landscape in wild mice, with a mother's influence on microbiota composition waning as offspring age, while the relative impact of social contacts grows.
哺乳动物的肠道微生物群会影响一系列与健康相关的表型，然而，关于自然种群中肠道微生物定殖宿主的传播途径的了解仍然有限。在这里，我们利用一个经过深入研究的野生林小鼠（黄胸鼠）种群，来研究垂直（母系）和水平（社交）传播途径如何在整个生命过程中影响肠道微生物群的组成。
我们识别出了母系传播（母亲与其后代之间的分类群共享）和社交传播（由社交网络预测的分类群共享）的独立信号，其相对强度会随着宿主年龄的增长而变化。在生命早期，肠道微生物群的组成由母系和社交关系共同预测，但到成年时，母系传播的影响变得无法检测到，只留下社交传播的信号。通过探究哪些分类群驱动了母系传播信号，我们在林小鼠中识别出了一个候选的母系传播细菌家族——毛螺菌科。
总体而言，我们的研究结果表明野生小鼠的传播格局在个体发育过程中发生变化，母亲对微生物群组成的影响随着后代年龄的增长而减弱，而社交接触的相对影响则增加。
