It was a fortuitous accident that ultimately lead to the discovery, according to researcher Kevin Verstrepen at the Katholieke Universiteit Leuven in Belgium. Upon returning to his lab over the weekend, Verstrepen discovered fruit flies, escapees from a neighboring genetics lab, had flocked to an open flask filled with yeast. But a flask containing a non-smelling mutant variety of yeast remained untouched.
The yeast in the untouched flask were missing a gene, the fungal aroma gene ATF1, which is responsible for the yeast's scent. When the researchers later presented the flies with air smelling of aromatic or unscented yeast, the insects flew toward the fruity-scented microorganisms, the authors write in the journal Cell Reports.