December 12, 2012
Honeybee Histone Code Found, Sheds Light On Development Changes
Lee Rannals for redOrbit.com — Your Universe Online
Researchers have uncovered a new element of the honeybee's genetic makeup, shedding light on why bees are so sensitive to environmental changes.
Scientists found honeybees have a "histone code," which is a series of marks on the histone proteins around which their DNA is wrapped to help fit into the nucleus of a cell. This code is known to exist in humans and other organisms in order to control changes in cell development.
This marks the first time the code has been discovered in the honeybee. These codes can also be affected by nutrition and environmental factors.
Scientists believe the findings may be another part of the puzzle that helps to explain how royal jelly ensures honeybee larvae turn into queens and not workers.
"The development of different bees from the same DNA in the larvae is one of the clearest examples of epigenetics in action — mechanisms that go beyond the basic DNA sequence," Dr. Mark Dickman from the University of Sheffield's Faculty of Engineering, said in a statement. "From our knowledge of how the histone code works in other organisms, we think that the marks on the histone proteins might act as one of the switches that control how the larvae develop."
The scientists wrote in the journal Insect Biochemistry and Molecular Biology their findings could help to open up the door for further study of the interplay between environment, nutrition and how the honeybee develops.
The first step in understanding honeybee development is to know how larval diet influences the histone code to ensure development into either a queen or a sterile worker.
"Indirect dietary-mediated effects are also of particular relevance to insect pollinators," Dr. Paul Hurd, from Queen Mary's School of Biological and Chemical Sciences, said in the statement. "Prime examples are from systemic pesticides used on agricultural crops, which accumulate inside nectar and pollen and therefore enter honey bee diet, in some cases with detrimental effect."
He said by studying the impact of diet and particular chemicals on the histone code during honeybee development and behavior, scientists could identify how certain pesticides contribute to the decline of colonies.
"We really need to begin looking beyond classical genetics to understand many of the current problems honey bees face including Colony Collapse Disorder," added Professor Ryszard Maleszka of the Australian National University.
"There are rarely single genes that cause a given disease; it's more often interactions between a number of genes that's heavily influenced by environmental factors," Maleszka said.
He said histone codes are flexible and have the capacity to act as an interface between genome and environment.