Gene of the Month - Happy Hour

And finally, it’s time for our gene of the month, and this time it’s Happy Hour.

If you’re anything like me, the only way to get through the dark nights of winter - not to mention the endless torrent of terrible global news - is to get drunk. But the difference between passing out after a single shot or only getting blotto after a whole bottle might be in your genes - at least, if you’re a fruit fly.

The Happy Hour gene was discovered in 2009 by researchers who took a bunch of fruit flies, plied them with alcohol, then looked for mutations that meant the flies stayed standing long after their regular comrades had keeled over drunk. These hardened insect boozers turned out to have a mutation in a gene involved in sending signals inside cells - making a type of enzyme known as a kinase. The Happy Hour gene normally works as part of the EGFR signalling pathway, which is involved in a huge range of fundamental biological processes including telling cells when to divide. Unsurprisingly, faults in EGFR signalling are linked to cancer but in the case of alcohol consumption, Happy Hour seems to be playing a role in the part of the fly brain that responds to  the chemical dopamine, which helps to control pleasure and reward.

Intriguingly, when the researchers gave normal flies a cancer drug that blocked EGFR signalling, they got knocked out by alcohol a lot faster than those who hadn’t taken the treatment. The same effect worked in mice and rats, eventually putting them off booze altogether, suggesting that this could potentially be a way to treat alcoholism in humans by making the unpleasant effects of alcohol kick in quicker.

Happy Hour isn’t the only fruit fly gene associated with alcohol metabolism. The same lab also discovered Cheapdate - flies with a mutation in this gene are super-sensitive to alcohol, the opposite to Happy Hour. The team also found a gene they called Hangover, which helps fruit flies become tolerant to alcohol over time. It’s unknown whether flies with a mutation in their Hangover gene can be found slumped in front of the TV on a Sunday morning, muttering “please just be quiet and bring me a bacon sandwich.”