Fruit fly helps scientists identify gene linked to humans’ alcohol consumption

Drunken fruit flies have helped an international team of scientists to identify a key gene associated with alcohol consumption in humans. The researchers believe understanding how the gene works may point to new kinds of treatments for alcohol use disorders.

The research involved studying the effect of alcohol on fruit fly behaviour, said Trinity College Dublin’s Prof Arun Bokde, who participated in the international effort.

The flies behave more or less like we do when given alcohol. Low doses make us and fruit flies more lively while a heavy dose knocks us out. Flies also show addiction-like behaviour much as we do.

With such familiar responses the team began looking for any genes linked to behaviour when under the influence and they found one.

Reduced sensitivity

“They found a gene in the fly that was associated with reduced sensitivity to alcohol,” he said. The flies acted drunk when the gene, called Rsu1, was working but the fly had reduced sensitivity to alcohol when the gene was not working correctly.

Humans have the same gene and the researchers, led by Prof Adrian Rothenfluh of the University of Texas Southwestern Medical Centre at Dallas decided to see whether it too was involved in behaviour when drinking.

The team put together a group of about 1,400 adolescents, none of whom exhibited signs of alcohol addiction, Prof Bokde said.

Brain imaging

They used brain imaging to show first that this gene in humans is associated with the brain’s reward system, the system that becomes activated when we use alcohol.

They then showed that the Rsu1 gene was linked to the frequency of lifetime drinking in an adolescent sample and alcohol dependence in an adult sample.

This supports the idea that the Rsu1 gene can affect our preferences for alcohol and our behaviour when drinking it.

Details of their findings are published in the US Proceedings of the National Academy of Sciences.

“The next step would be to look at the molecular function of this gene to understand what it is doing in the brain,” Prof Bokde said. “It is a potential target to treat alcohol addiction. The gene is associated with a reward system. If you can change that reward anticipation you might be able to modify alcohol related behaviours,” he said.