The influence of the B4galnt2 gene and host population structure on the intestinal microbiota in house mice

栖息在哺乳动物胃肠道中的微生物群落在宿主生物学的各个方面发挥着重要作用。然而，关于这些群落中形成变异的力量及其对宿主适应度的影响，人们知之甚少。由于与血型相关的糖基转移酶是自然选择的常见目标，并影响胃肠道中致病菌和共生细菌的附着和定植，因此它们代表了描述形成宿主-微生物群相互作用的进化力量的良好候选者。与血型相关的糖基转移酶基因B4galnt2在天然家鼠种群中受到强烈的选择力的影响，其中含有一种常见的等位基因变体，该等位基因变体特异性地关闭了胃肠道中的基因表达，并且在当地种群之间的频率差异很大。本研究的目的是：(i)在群体基因组水平上分离和表征肠道群落中B4galnt2基因型适应的成员，（ii）表征自然群体中病原体驱动的选择，（iii）分析肠道细菌群落的多样性及其小鼠宿主的群体结构。

The microbial communities inhabiting the mammalian gastrointestinal tract play an important role in diverse aspects of host biology. However, little is known regarding the forces shaping variation in these communities and its influence on host fitness. Because blood group-related glycosyltransferases are frequent targets of natural selection and influence the attachment and colonization of both pathogenic and commensal bacteria in the gastrointestinal tract, they represent good candidates for describing the evolutionary forces shaping host-microbiota interactions. The blood group-related glycosyltransferase gene B4galnt2 is subject to strong selective forces in natural house mouse populations, which contain a common allelic variant that specifically turns off gene expression in the gastrointestinal tract and greatly varies in frequency between local populations. The aims of this proposal are to (i) isolate and characterize B4galnt2 genotype-adapted members of intestinal communities at the population genomic level, (ii) characterize pathogen-driven selection in natural populations and (iii) analyze the diversity of intestinal bacterial communities with respect to the population structure of their mouse host.