In a scientific first, US researchers led by Dr Andrew Feinberg at Johns Hopkins University have shown how complex animal behaviours can be controlled by a subtle manipulation of the DNA structure, known as DNA methylation, which does not change the DNA sequence. Known as epigenetics, this represents the next chapter in our understanding of molecular biology.
This pioneering study was carried out in the humble honeybee – a highly sociable animal where, within each hive, different types of bees have distinct roles and responsibilities.
There are three types of bees in any hive. First is the queen bee, which is the only bee capable of laying eggs. Second are the drone bees, the only males in the hive, who are responsible for fertilising the eggs that the queen lays. Finally there are the female, but infertile, worker bees that have two main subgroups: the nurses, which look after the queen, and foragers, which find pollen and bring it back to the hive.
The foragers and nurse bees share exactly the same genetic code but their innate behaviour is completely different. By examining DNA derived from the two populations Dr Feinberg and his team confirmed that these bees have identical genetic sequences but in over 100 different regions of their DNA strands they have quite different epigenetic profiles.
When they examined the hives in greater detail they made a startling discovery - many workers start their lives as nurses and, once mature, become foragers, but if needs dictate they can revert back to nurses, clearly suggesting that the DNA methylation process is completely reversible.
These discoveries could have great implications for studying human cognition and psychology and could perhaps shed light on how the human brain regulates complex entities like mood, learning, and belief systems.
Posted on Tuesday, 16th October, 2012