For a honey bee, few things are more important than recognizing your nestmates. Being able to tell a nestmate from an invader could mean the difference between a honey-stocked hive and a long, lean winter.
New research from Washington University in St. Louis shows that honey bees rely on chemical cues related to their shared gut microbial communities, instead of genetic relatedness, to identify members of their colony.
“Most people only pay attention to the genetics of the actual bee,” said Yehuda Ben-Shahar, professor of biology in Arts & Sciences and corresponding author of the study published Oct. 14 in Science Advances. “What we show is that it is genetic, but it’s the genetics of the bacteria.”
Honey bees recognize and respond to chemical signals from other bees that they detect from skin compounds known as cuticular hydrocarbons, or CHCs. This study determined that a bee’s particular CHC profile is dependent on its microbiome — the bacteria that make up its gut microbial community — and is not something innate or genetic to the bee alone.
“Different colonies do in fact have colony-specific microbiomes, which has never been shown before,” said Cassondra L. Vernier, postdoctoral associate at the University of Illinois, who earned her biology PhD working with Ben-Shahar at Washington University.
“Bees are constantly sharing food with one another — and exchanging this microbiome just within their colony,” said Vernier, first author of the new study.
Co-authors include Gautam Dantas, professor of pathology and immunology and of molecular microbiology at Washington University School of Medicine in St. Louis, and Joel Levine at the University of Toronto Mississauga. The work was conducted in part with bees housed at Tyson Research Center, the environmental field station for Washington University.
“The importance of this paper is that it’s one of the first papers that actually shows that the microbiome is involved in the basic social biology of honey bees — and not just affecting their health,” Vernier said. “The microbiome is involved in how the colony as a whole functions, and how they are able to maintain nest defenses, rather than just immune defense within an individual.”