Meeting Abstract
The developmental environment, including the maternal microbiome (the community of symbiotic bacteria that regulates diverse host processes), can have a lasting effect on offspring phenotypes. In mammals, the microbiome was traditionally thought to establish in the postnatal period after exposure to the maternal vaginal tract. However, recent studies in mice suggest prenatal transfer of maternal microbes via the placenta. This prenatal inoculation is thought to promote the development of the mucosal immune system in offspring. While environment and diet play large roles in shaping microbiota composition, mounting evidence suggests that host genotype also plays an important role. However, the degree to which offspring genotype influences the composition of the prenatally-transferred community is unknown. To fill this gap we crossed two closely related mouse species, Mus musculus domesticus and Mus spretus. M. m. domesticus (n = 10), M. spretus (n = 11), and hybrid (n = 9) placentas were collected in late gestation at embryonic day 17.5. Microbial DNA was extracted and the V4 region of the 16S rRNA gene was sequenced for each placental genotype. If the composition of the placental microbiome depends only on maternal species, we should see no difference in community composition between hybrid placentas carried by M. m. domesticus mothers and M. m. domesticus placentas. If, however, offspring genotype plays a role in determining placental microbial composition, hybrid placentas should be distinct from both parental species. This project will provide a first step in understanding the impact of offspring genotype on microbial community composition during gestation.
