Evolutionary and Functional Insight Into Gut Microbial Community Diversity Across Honeybee Species Using Metagenomics

Abstract:

Honeybees harbor specialized microbial communities in their gut, which makes them exciting models for understanding the evolution of gut microbiota-host interactions across animals. However, while the gut microbiota of the managed and globally distributed Western honeybee (A. mellifera) is well studied, little is known about the communities present in the gut of wild honeybee species mainly found in Asia. In particular, the dearth of genomic data has limited our understanding of the functional potential and evolution of gut microbes across honeybees. We find that the size of the microbial community varied across host species, with the giant honeybee, A. dorsata, harboring the largest number of magOTUs per bee, followed by A. mellifera and A. cerana, and then the dwarf honeybee, A. florea and its closest relative, A. andreniformis. Moreover, most of the identified community members had a host-restricted distribution, i.e., magOTUs were usually associated with only one particular host species, independent of geography. Additionally, when magOTUs were shared, gene flow analyses suggested host-specific strain-level populations. Finally, in A. dorsata and A. cerana, several predominant magOTUs belonged to genera that were not formerly known to be important core microbiota members of social bees and are absent in managed honeybees. Strikingly, some of these magOTUs contain diverse arsenals of pectinase, hemicellulase and cellulase genes, suggesting that they represent overlooked key symbionts of honeybees with important functions for the breakdown and digestion of the recalcitrant pollen diet of honeybees. We are currently mapping out how the metabolic network of the gut microbiome changes across host species based on the metagenomic data. This will shed light on the implication of host specificity of taxa on the functional potential of the community and their evolution.

Speaker's Profile:

Aiswarya Prasad is currently a PhD student at University of Lausanne under the supervision of Prof. Philipp Engel. She completed her Master’s in Biology at the Indian Institute of Science, Bangalore.