Scientists at Queen Mary University of London and Australian National University have unraveled how changes in nutrition in the early development of honey bees can result in vastly different adult characteristics.
Queen and worker honey bees are almost genetically identical, but receive a different diet as larvae. The researchers have found that specific protein patterns on their genome play an important role in determining which one they develop into.
These proteins, known as histones, act as switches that control how the larvae develop. Diet determines which switches are activated. They found that the queen develops faster and the worker developmental pathway is actively switched on from a default queen developmental program.
This change is caused by epigenetics – a dynamic set of instructions that exist ‘on top’ of the genetic information. Epigentic modifications encode and direct the program of events that leads to differential gene expression and worker or queen developmental outcome.
The study, published in Genome Research, describes the first genome wide map of histone patterns in the honey bee and the first between any organism of the same sex that differs in reproductive division of labor.
Bees are also very important pollinators – so it is crucial to understand their molecular biology, how they develop and the mechanisms that regulate this.
Lead author Dr Paul Hurd, from Queen Mary University of London, said: “The ability of an individual larva to become a worker or a queen is due to the way genes are switched on or off in response to the specific diet; this determines such differing outcomes from the same genome.”
“We show that queens and workers have specific histone patterns even though their DNAs are the same. These proteins control both structural and functional aspects of the organism’s genetic material and have the capacity to determine which part of the genome, and when, has to be activated to respond to both internal and external stimuli.”
The histones have small chemical tags, or epigenetic modifications, that allow them to act differently to those that do not, usually by ….