AsianScientist (Aug. 10, 2016) – Scientists in Australia are a step closer to protecting honey bees from a sexually transmitted disease that causes dysentery and weakens hives considerably. The study was published in the Journal of Proteome.
During the past 20 years there have been dramatic declines in bee populations globally as a result of bee diseases, parasites and exposure of bees to pesticides. On the other hand, Western Australia has some of the healthiest honey bees in the world due to geographic isolation, biosecurity measures and the banning of pesticide use on hives.
A team at The University of Western Australia’s Center for Integrative Bee Research (CIBER) investigated how male honey bees (Apis mellifera) responded to an infection with the sexually transmitted fungal parasite Nosema apis. The researchers unraveled how sick males mounted a highly specific immune response against the parasite, by suppressing the parasite in the ejaculate using immune molecules in the seminal fluid.
Using a technique called iTRAQ isotopic labeling, the researchers discovered in infected males changes to the levels of 111 of the 260 seminal fluid proteins tested. Of this dataset, 15 proteins have well-known immune-related functions, including two chitinases previously hypothesized to be involved in honey bee antifungal activity against N. apis.
Research fellow Dr. Julia Grassl, who is the lead author of the study, said it was amazing to discover the whole complexity of the insect immune system activated inside the seminal fluid surrounding sperm.
“We already knew that substances in bee semen were able to recognize and kill Nosema apis very efficiently,” Grassl said. “However, it is surprising how quickly sick males can activate an efficient response to protect their sperm and ultimately the queen against the disease during mating.”
The identified immune molecules might help breed more disease-tolerant bees in the future, or be developed into a bee-derived medication to heal parasite-infected hives, the researchers say.
The article can be found at: Infections with the Sexually Transmitted Pathogen Nosema apis Trigger an Immune Response in the Seminal Fluid of Honey Bees (Apis mellifera).
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Source: University of Western Australia; Photo: Shutterstock.
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