Open Sesame – the chemical power needed to enter the hive.

Do you want to know how bees communicate with each other and recognize themselves? It could be all about bacteria.

Breaking down the microbiology world one bite at a time

Open Sesame – the chemical power needed to enter the hive.

Honeybee colonies are highly guarded at their doors, and one needs the right chemical formula to be able to enter the hive, but where does it come from?

Insects communicate with their skin. The first layer – the cuticle – is covered with cuticular hydrocarbons used both as a desiccation barrier as well as for communication. Different blends of these cuticular hydrocarbons can be used to indicate colony membership in bee communities.

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Due to the close genetic background of the colony members, it has been long thought that mostly genetics would be the main driver in these recognition signals, or it would be most likely due to the honeybees environment, or even individual chemical signals in the hive that would then be passed on to the colony.

However, up to now it’s still unclear what the main driver for these chemical signals is. In a recent study, Vernier et al. hypothesized that it could be due to the honeybee gut microbiota. Many studies have indeed published the question of gut microbiota role in social behaviors in other species, including humans. 

Vernier and colleagues looked at the microbiota composition in different bees from different colonies and showed that they did harbor different communities. To better understand the role of the gut microbiota they conducted several experiments:

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All these experiments indicated that different chemical signatures come from different gut microbiota.

Authors are still unsure on the mechanisms, but they think it could be due to the ability of the gut bacteria to either provide or suppress precursor metabolites, or by modulating the expression or activity of host genes involved in the synthesis of the chemical signals.

How does this benefit the gut bacteria? Well, we cannot know for sure but the authors suggest that since the chemical signals are very important for recognition of colony members they prevent the invasion of outsiders. This will then limit the transmission of other new strains of bacteria into the colony, and thus reduce bacterial competition within it.

Original paper : C. L. Vernier, I. M. Chin, B. Adu-Oppong, J. J. Krupp, J. Levine, G. Dantas, Y. Ben-Shahar, The gut microbiome defines social group membership in honey bee colonies. Sci. Adv. 6,
eabd3431 (2020).

Doi: 10.1126/sciadv.abd3431