Infection dynamics of Nosema ceranae in honey bee midgut and host cell apoptosis

•Dynamics of Nosema ceranae infection in honey bee midgut.•Host cell apoptosis was most severely decreased in the posterior epithelium of sensitive bees.•Apoptosis in Nosema tolerant bees remained unchanged. Nosema ceranae is an intracellular microsporidian parasite that infects epithelial cells of the honey bee (Apis mellifera) midgut. Previous studies have shown that Nosema may alter cell renewal and apoptosis in honey bees. We found that the amount of apoptotic cells progressively declines from the anterior towards posterior regions of the midgut in Nosema-infected sensitive bees. There was no such pattern in the infected Nosema tolerant honey bees and controls. These data provide additional evidence that N. ceranae appears to alter apoptosis in its host cells for its own advantage.