Genetic divergence and functional convergence of gut bacteria between the Eastern honey bee Apis cerana and the Western honey bee, Apis mellifera

Authors: WU, YUQI - Zhejiang University; ZHENG, YUFEI - Zhejiang University; WANG, SHUAI - Zhejiang University; Chen, Yanping - Judy; TAO, JUNYI - University Of Miami; CHEN, YANAN - Zhejiang University; CHEN, GONGWEN - Zhejiang University; ZHAO, HONGXIA - Guangdong Academy Of Agricultural Sciences; WAI, KAI - Chinese Academy Of Sciences; DONG, KUN - Yunnan Academy Of Agriculture Sciences; HU, FULIANG - Zhejiang University; FENG, YE - Zhejiang University; ZHENG, HUOQING - Zhejiang University

Submitted to: mSystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2021
Publication Date: 8/10/2021
Citation: Wu, Y., Zheng, Y., Wang, S., Chen, Y., Tao, J., Chen, Y., Chen, G., Zhao, H., Wai, K., Dong, K., Hu, F., Feng, Y., Zheng, H. 2021. Genetic divergence and functional convergence of gut bacteria between the Eastern honey bee Apis cerana and the Western honey bee, Apis mellifera. mSystems. 37:19-31. https://doi.org/10.1016/j.jare.2021.08.002.
DOI: https://doi.org/10.1016/j.jare.2021.08.002

Interpretive Summary: Gut bacteria play an important role in modulating host function and health. The Asian honey bee and European honey bee are derived from the same ancestor yet have evolved different life strategies. The similarities and differences in gut bacteria composition and richness between these two sister species remain largely unexplored. In this study, we conducted comparative genetic analysis of gut bacteria of the Asian honey bee and European honey bee. Our results showed that, while intra-species diversity exists, the richness and overall gut microbial composition of the two honey bee species are remarkably similar. Our results also showed that gut bacteria from the Asian honey bee and European honeybee could cross-colonize between the two species. These findings reflect their shared behavior, life history traits and ecological niches. The information about the honey bee gut bacteria obtained from this study can be used to delineate species and their unique characteristics, and should be of interest to scientists, academics and beekeepers around the globe.

Technical Abstract: Background: The functional relevance of intra-species diversity in natural microbial communities of honey bees remains largely unexplored. Two closely related honey bee species, Apis cerana and Apis mellifera have their guts colonized by a similar set of core bacterial species that are composed of host-specific strains, therefore providing a good model for an intra-species diversity study. Results: Here, we used shotgun metagenomic approach to assess the intra-species diversity of gut microbiota of A. cerana and A. mellifera. Comparative analysis of both nucleotide polymorphism and gene contents showed that the strain composition of core bacterial species is host-specific.Except for Bartonella apis. these core bacterial species presented a distinctive functional profile between hosts. Unexpectedly, we found that the overall functional profiles of A. cerana and A. mellifera gut microbiome are remarkably similar. This finding was further supported by the consistency of the bees' gut metabolome. A cross-species gut bacteria colonization assay demonstrated that gut microbiota of A. cerana and A. melliferacould cross colonize between the two bee species. Conclusion: Our findings revealed that the intra-species diversity between A. cerana and A. mellifera leads to a functional difference of core gut bacteria. However, the functional profiles of the overall gut microbiome converge between the two bee species, probably resulting from their overlapped ecological niches. Our findings provide critical insights into functions of the mutualistic microbiota of bees and , revealed that the functional redundancy could remarkably stabilize the functional difference at the strain level within the gut community.