We will investigate the composition of the microbiota of wild rodents by 16S-amplicon sequencing. Initially, we will focus on the microbiota in the upper respiratory tract, but the project can be expanded to include the gut microbiota too. We are primarily interested in comparing the composition of the microbiota of different rodent species sampled in the wild. Our previous studies have shown that different species have very different immune systems (based on analyses of immune responses by means of RNA-sequencing of spleen transcriptomes). We now want to test if this interspecific variation in immune function is associated with interspecific variation in the composition of the microbiome.