Infections with the sexually transmitted pathogen Nosema apis trigger an immune response in the seminal fluid of honey bees (Apis mellifera)
Honey bee (Apis mellifera) males are highly susceptible to infections with the fungal pathogen Nosema apis. However, they are able to suppress this parasite in the seminal fluid using immune molecules. We predicted that infected males would respond to infections by altering the seminal fluid proteome in order to minimize the risk to sexually transmit the parasite to the queen, and thereby severely weakening her entire colony. We used iTRAQ isotopic labelling to compare seminal fluid proteins from infected and non-infected males and found that N. apis infections resulted in significant abundance changes in 111 of the 260 seminal fluid proteins quantitated. The largest group of proteins with significantly changed abundances consisted of 15 proteins with well-known immune-related functions, which included two significantly more abundant chitinases in the seminal fluid of infected males. Chitinases were previously hypothesized to be involved in honey bee antifungal activity against N. apis. Here we show that infection with N. apis triggers a highly specific immune response in the seminal fluid of honey bee males.
Sexually transmitted disease, Host parasite interactions, Antimicrobial proteins,