Researchers from North Carolina State University studying fruit flies have found genetic links to alcohol sensitivity, suggesting why some people are more tolerant of alcohol consumption, and therefore at higher risk of alcoholism, the Daily Telegraph reported Oct. 31.

Like human beings, fruit flies can become intoxicated, which can be detected through movement problems and sleepiness. Tatiana V. Morozova and colleagues identified 23 fruit fly genes that have human equivalents, allowing them to transfer their findings to the human population. 

The research team bred fruit flies over 25 generations into two groups, those highly sensitive to alcohol ("lightweights") and those highly tolerant ("lushes"). About 1,500 genes were linked in some way to the difference between "lightweights" and "lushes", and 32 mutated genes were revealed through tests to directly affect sensitivity to alcohol.

Fruit flies were exposed to alcohol vapors through an "inebrioimeter," a long vertical tube with platforms onto which the flies could cling. As the flies became inebriated, they would fall from platform to platform until they collapsed at the bottom of the tube. "Lightweights" collapsed after a minute or two of exposure to the vapors, while "lushes" lasted about 18 minutes.

The research was published in the journal Genome Biology.