Diet affects reproductive development and microbiota composition in honey bees

Area of Science:

• Animal Science
• Microbiology
• Ecology

Background:

• Gut microbes are crucial for animal health, but complex host factors obscure their impact.
• Honey bees offer a simplified model for studying host-microbe interactions due to their tractable gut microbiota.
• Worker honey bees exhibit distinct gut microbiota from queens, despite shared environments and genetics.

Purpose of the Study:

• To investigate if diet and/or reproductive development influence gut microbiota in worker honey bees.
• To understand factors driving gut microbial differences between honey bee queens and workers.
• To explore honey bees as a model for host-microbe dynamics.

Main Methods:

• Newly emerged, microbiota-depleted workers were reared under varied diets and pheromone conditions.
• Workers were exposed to queen or worker gut homogenates.
• Ovary development and gut microbial communities were analyzed three weeks post-emergence.

Main Results:

• Reproductive development (ovary formation) increased with absence of Queen Mandibular Pheromones (QMP) and queen-biased diet (royal jelly).
• Diet, not reproductive development or pheromone exposure, was the primary driver of "queen-like" microbiota in workers.
• Diet alone could not fully account for the observed worker gut microbiota composition.

Conclusions:

• The hypothesis that reproductive development drives microbiota differences between queens and workers was rejected.
• Diet is a major factor, but not the sole determinant, of distinct gut microbial communities in honey bee queens and workers.
• Behavioral and other physiological factors likely contribute to the unique microbiota of queens and workers, highlighting honey bees as a valuable model system.