July 21, 2014
Gene Activity Associated With Diet Of Honey Bees Could Play Role In Colony Collapse Disorder
redOrbit Staff & Wire Reports - Your Universe Online
In a new study designed to determine whether or not poor nutrition plays a role in colony collapse disorder, researchers from the University of Illinois, Urbana-Champaign have discovered that there are significant differences in the genetic activity in honey bees based on the type of food the insects consume.
The research, which was published online in the journal Scientific Reports, specifically focused on an energy storage tissue in Western honey bees called the fat body, which functions like the liver and fat tissues found in humans and other vertebrates.
“We figured that the fat body might be a particularly revealing tissue to examine, and it did turn out to be the case,” lead investigator, University of Illinois entomology professor and Institute for Genomic Biology director Gene Robinson explained in a statement.
As the researchers explained, some beekeepers tend to feed sucrose or high-fructose corn syrup to their honey bees during times when nectar is lacking in the hive. However, some have decried the practice due to the spread of colony collapse disorder – the massive and currently unexplained annual die-off of honey bees in the US and Europe.
Robinson and entomology graduate student Marsha Wheeler set out to determine if inadequate nutrition was a factor in the insect population’s decline. The researchers opted to focus solely on foraging bees, since they tend to be older, have higher metabolic rates and less energy reserves in the form of stored lipids than hive-bound bees.
As a result, Robinson said, that makes the foragers far more dependent upon carbohydrate-rich diets – and, theoretically at least, “more sensitive to the effects of different carbohydrate sources.” He and Wheeler analyzed gene activity in response to consumption of honey, high-fructose corn syrup (HFCS) or sucrose.
The researchers found that bees that had been fed honey had a vastly different profile of gene activity in the fat body than those consuming either HFCS or sucrose, with differences in activities observed in hundreds of genes. Furthermore, those differences remained even in an experimental hive that the study authors later discovered had been infected with deformed wing virus, a condition which affects honey bees all over the world.
Some of the genes impacted by dietary changes included have been linked to protein metabolism, brain-signaling and immune defense, the Illinois researchers noted. The latter supports previous research by the university which linked some substances in honey with increased activity in genes that helped honey bees break down pesticides and other potentially toxic substances.
“Our results parallel suggestive findings in humans. It seems that in both bees and humans, sugar is not sugar -- different carbohydrate sources can act differently in the body,” Robinson said. “Our results further show honey induces gene expression changes on a more global scale, and it now becomes important to investigate whether these changes can affect bee health.”
Back in February, a study from EcoHealth Alliance looked at the potential caused of colony collapse disorder, finding that pests, pathogens and management issues likely played a major role in the long-term reduction in colonies in the US, Europe and elsewhere. In addition, the study reported that the reduction in bee colony numbers in recent decades reflects an overall decrease in the profitability of beekeeping, leading many to abandon the profession.