Gut microbial signatures associated with sexual maturity and oviposition behaviors in bumble bee queens

Authors: WANG, LIUHOA - Chinese Academy Of Agricultural Sciences; LI, KAI - Chinese Academy Of Agricultural Sciences; SADD, BEN - Illinois State University; GUO, YULONG - Chinese Academy Of Agricultural Sciences; ZHUANG, DAOHUA - Non ARS Employee; Chen, Yanping - Judy; Evans, Jay; JIE, WU - Chinese Academy Of Agricultural Sciences; ZHANG, ZHIGANG - Yunnan University; LI, JILLIAN - Chinese Academy Of Agricultural Sciences

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2019
Publication Date: 12/10/2019
Citation: Wang, L., Li, K., Sadd, B.M., Guo, Y., Zhuang, D., Chen, Y., Evans, J.D., Jie, W., Zhang, Z., Li, J. 2019. Gut microbial signatures associated with sexual maturity and oviposition behaviors in bumble bee queens. Insects. 4(6):e00631-19. https://doi.org/10.1128/mSystems.00631-19.
DOI: https://doi.org/10.1128/mSystems.00631-19

Interpretive Summary: Bumblebees are important wild pollinators of agricultural crops and wild plants across the world. The queen is the sole reproductive female in a colony and has the longest life among colony members. Consequently, queen health is pivotal to colony productivity and longevity. The gut bacteria greatly impacts the health of animals including bumblebees. In present study, we conducted a study to investigate the gut bacterial communities in queens of bumblebees. Our results yielded important information on the composition and diversity of gut bacteria in unmated queens, mated queens, and queens that lay eggs, which is useful for future to study the gut bacteria function in queen development and colony's performance. The knowledge gained from this study should be of interest to the researchers, graduate students, beekeepers and policymakers worldwide.

Technical Abstract: Background: Bumble bees (genus Bombus) are important pollinators in natural and agricultural ecosystems. Colonies of these social insects are founded by individual queens, which live throughout the colony life-cycle as the predominant reproductive, contributing to colony productivity through worker production and fitness through males and new queens. Therefore, queen health is paramount. There has been an increasing emphasis on the role of gut microbiota for animal health, including bees, yet there is limited information on gut microbial dynamics of bumble bee queens. We address how the developmental stage and physiological state of queens influences gut microbiota composition. Results: We employed a metagenomic bacterial 16S rRNA approach in conjunction with quantitative PCR to investigate the diversity and composition of gut bacterial communities in unmated, mated and ovipositing queens of the bumble bee Bombus lantschouensis. Our study generated 2,107,642 high-quality reads that were clustered into 390 operational taxonomic units (OTUs) spanning 20 phyla and 199 genera. We found significant shifts in the microbial composition across queen states, with specific microbiome signatures being associated with different stages. Unmated and ovipositing queens showed the greatest similarity in community composition, with mated queens being distinct. Gilliamella, Snodgrassella, Lactobacillus were the relatively dominant bacterial genera in both unmated and ovipositing queens, with Bifidobacterium additionally dominant in ovipositing queens. Bacillus, Lactococcus and Pseudomonas increased following queen mating. However, further analysis of unmated queens covering the ages of the mated queen group showed the differences seen in mated queens occurred independent of the occurrence of mating. Conclusions: Our results suggest a relationship between bumble bee queen gut bacteria and their development stage and physiological status. Our study is the first to explore the gut microbiome of bumble bee queens and provides useful information for future studies of the function of gut bacteria in queen development and colony performance.