Bees have experienced a slow genocide over the past decades. Their number has dropped significantly due to the collapse syndrome of bee colonies, which is associated with the action of a number of negative factors, including the cultivation of agricultural monocultures, the use of pesticides from the neonicotinide class.
But the main culprits of the epidemic are DWV viruses, which cause deformation of the wings, as well as the parasitic mites Varroa destructor, which infect the fatty bodies of bees and often carry viruses. However, Nancy Moran and her colleagues at the University of Texas at Austin seem to have found a method to make bees immune to tick and virus attacks.
To do this, they used bacteria, natural representatives of the intestinal microflora of bees, and modified their genome, turning microbes into defenders of their hosts, deadly to parasites. Scientists talk about their work in an article published in the journal Science.
The authors used the ability of RNA to suppress the work of certain genes. It is known that these molecules serve as mediators that transfer information from DNA to the ribosome, where a protein is synthesized on the basis of an RNA template. However, regulatory small RNAs can bind to the appropriate messenger RNA, "deactivating" it and thereby inhibiting the expression of the corresponding gene. This process is called RNA interference, it is increasingly being used in science and medicine, and in 2006 the Nobel Prize was awarded for its study.
American geneticists decided to use interfering RNAs to suppress the work of key genes of viruses and ticks that cause collapse of bee colonies. It is not necessary to interfere with the genome of the insects to produce the desired molecules. Unlike people with our varied and complex diets, bees have a rather limited diet and their intestinal microflora is not very diverse.
The human intestinal microflora can include hundreds and thousands of different types of bacteria; bees have only six to eight of them. This allows us to believe that the new method will easily "take root" in populations around the world, although so far it has been tested only in the laboratory, and field trials are still pending.
So, the authors modified the symbiotic bacteria of bees Snodgrassella alvi, "teaching" them the mass production of RNA capable of interfering with the work of a number of key genes vital for DWV or for varroa. GM bacteria were fed to 20 experimental insects before being exposed to the parasites.
And indeed: when meeting with such bees, the mortality among ticks jumped by 70 percent, and the mortality of the bees themselves from DWV was 37 percent lower than that of insects that did not have GM microbes. Experiments have shown that such protection lasts for at least 15 days - monitoring has not been carried out for longer. Moreover, the new bacteria were passed on during the feeding of the young, which gives hope that this protection can be preserved from generation to generation.