Dynamic and Asymmetric Changes of the Microbial Communities after Cohousing in Laboratory Mice

Abstract

Summary: Horizontal transmission of the microbiota between different individuals is widely used to normalize the microbiota in laboratory mice. However, little is known about the dynamics of microbial communities and the level of microbiota transmission after cohousing. We extensively analyzed the fecal microbiota in Jackson and Taconic C57BL/6 mice to study horizontal transmission after weaning. Changes in the microbiota were clearly detected on day 3, almost plateaued on day 7, and resulted in near-comparable composition by day 28 after cohousing. Notably, the transmission of bacterial species was asymmetric in kinetics and abundance, resulting in a microbiota that is more similar to that of Jackson mice than Taconic. Several operational taxonomic units (OTUs) increased their abundance rapidly after cohousing in Taconic mice whereas several OTUs including two mucus-associated bacteria increased their abundance with delayed kinetics in Jackson mice. These studies provide insight into the dynamics and normalization of the microbiota during horizontal transmission. : Caruso et al. present a comprehensive analysis of horizontal transmission of the fecal microbiota between mouse populations from two common vendors after cohousing. These studies validate the requirement of cohousing for microbiota normalization and will guide researchers who perform experiments with the gut microbiota. Keywords: microbiota normalization, age-dependent change of microbiota, horizontal transmission, Jackson mice, Taconic mice, cohousing-dependent microbiota transition, fecal microbiota, Illumina MiSeq 16S rRNA gene sequencing, mother, sex- and age-independent changes of microbiota