Lexi Hoopman (Biology) received new funding from the US Department of Agriculture for the project “The unintended antibiotic target: (honey bee) microbiome and fecundity.” Dr. Kasie T. Raymann is faculty mentor on the project.
Tetracyclines are the most commonly used antibiotic to treat disease in humans and livestock, including honey bees for treatment and prevention of disease. Like other antibiotics, oxytetracycline is classified as an endocrine disrupting chemical because of its mitochondrial inhibition in reproductive cells. Oxytetracycline has been shown to decrease human sperm motility and viability, in-vitro. In rats and mice, oxytetracycline reduced spermatogenesis, reproductive fertility and induced testicular damage.
Historically, a honey bee queen’s lifespan was 2-7 years, but now 50% of colonies replace their queens within six months. A colony will replace their queen for several reasons, including a lack of stored sperm, doubling the risk of colony mortality. In fact, colonies that are failing have queens with low sperm viability. It is unclear what factors affect drone (male) reproduction, but it is known that their sperm counts are highly variable.
Given the importance of queen reproductive success to colony survival, it is imperative to determine the factors contributing to diminished reproductive quality in both queens and drones. Additionally, the gut microbiome has been shown to play a role in growth and development of honey bee workers but its importance in queen and drone health and reproductive development are unknown. Therefore, the researchers will investigate the reproductive microbiome as well as the connection between gut and reproductive function. We will determine 1) how antibiotics impact the reproductive health of queens, 2) how antibiotics impact the reproductive health of drones, and 3) the link between the gut microbiome and reproduction in honey bees.