Gender differences in nature are common, including in humans. A research team from Bern, Switzerland has found that male European honey bees, or drones, are much more susceptible than female European honey bees, known as workers, to a fungal intestinal parasite called Nosema ceranae. Originally from Asia, Nosema ceranae has rapidly spread throughout the world in recent years, and may contribute to the high number of colony deaths now observed in many regions of the northern hemisphere. These findings demonstrate the delicate nature of male honey bees, which are important to honey bee colony reproduction, to a well-distributed parasite.
Honey bees are complex social organisms that demonstrate haploid-diploidy. The two female castes, workers and queens, are diploid like humans. They contain two copies of each chromosome. Male honey bees, known as drones, on the other hand are haploid and contain only one chromosome set. The haploid susceptibility hypothesis predicts that haploid males are more prone to disease compared to their diploid female counterparts because dominant genes on one chromosome copy have the op- portunity to mask mutated genes on the other copy in diploid organisms.
A research team from the Vetsuisse Faculty of the University of Bern recently demonstrated in an article in the open-access journal PLOS ONE that male honey bees are significantly more susceptible (they die sooner and have poor body condition) to an exotic fungal intestinal parasite called Nosema ceranae compared to female worker honey bees. The parasite, originally from Asia, has recently spread to possess a near global-distribution during a period of high honey bee colony losses in many global regions. Because of its recent detection in honey bees outside of Asia, researchers are scrambling to understand the parasite.