Bee calamity clarified

An illness that has been decimating US honeybees for more than three years probably isn't caused by a single virus, but by multiple viruses that wear down the bees' ability to produce proteins that can guard them against infection, according to a new study. Cells taken from bees that had succumbed to colony collapse disorder (CCD) were cluttered with ribosomal RNA fragments, suggesting that the bees had trouble translating genetic material into functional proteins, Berenbaum and her colleagues report today (August 24) in the Proceedings of the National Academy of Sciences. Berenbaum and colleagues at the US Department of Agriculture screened thousands of transcripts in the guts of bees from both healthy and CCD-stricken colonies from the east and west coasts of the US. CCD bees had several unusual RNA fragments resulting from broken, malfunctioning ribosomes. Multiple infections with a family of viruses called the picorna-like viruses, which seem to especially afflict CCD bees, could cause the appearance of such RNA fragments as they overwhelmed ribosomes and limited the cells' ability to manufacture functioning proteins. Bees that are not able to make proteins cannot mount effective responses to viral or bacterial infection or respond to dietary shortages, Berenbaum said. Although the study didn't uncover a single cause for CCD, said Dan Weaver, a Texas-based apiculturist who was not involved with the research, it "provides some hints and suggestive evidence that maybe there's a general impairment of bees' ability to cope with pathogens at a basic regulatory step."...TheScientist