Acetobacter to Lactobacillus Ratios within Drosophila Melanogaster Microbiota, Diet and Environment Across a Latitudinal Gradient
Authors: Aubrey Johansen; Amanda Morrison; Emma Davis
Affiliation: Brigham Young University, Provo, UT
Keywords: b. population variation; m. microbiome
The community of microorganisms associated with an organism (‘microbiota’) can be tightly linked to the evolution and life history variation of that organism in the wild. Therefore, patterns in the composition of these microbial communities are likely to be linked to the adaptive traits and evolution of their hosts. Our lab previously identified a pattern in the abundance of the two dominant bacterial groups in wild Drosophila from two locations in the United States: acetic acid bacteria (AAB) are more abundant at low latitudes and lactic acid bacteria (LAB) are more abundant at high latitudes. While this variation in microbiota composition can be attributed at least in part to host genotype, the likely role of environmental sources of microbes in determining the AAB:LAB ratio of wild flies have not been clearly defined. In this work we define how variation in environmental reservoirs of microorganisms are linked with variation in microbiota composition of the flies from two locations in the United States. We sampled flies, their diets, and soil from thirteen orchards located in the eastern United States and northern Utah, USA. We are currently working to sequence the microbiota of these samples and compare the LAB:AAB ratios between flies and their environmental substrates to determine if there is congruence in overall microbiota composition or abundance of specific microbial groups. Our early analyses on a subset of samples suggests the abundance of LAB in flies and their diets are coupled, although the initiating cause of this coupling has not yet been identified. Our continued work with these and additional samples will test if this pattern is reproducible in multiple locations and if other microorganisms also display covariation between flies and their diets. Together, these approaches will help define the role of environmental sources of microbes in determining microbial compositions in wild Drosophila populations.