Despite Homophila's spooky homepage, human geneticists curious to know what their disease gene does in Drosophila have nothing to fear. Ethan Bier and his colleagues at UCSD have compared the gene sequences entered in the Online Mendelian Inheritance in Man (OMIM) database to the genes, EST or genomic sequences in Flybase, the Drosophila sequence database. There is a story behind the creation of this web site. After finding that 74.5% of 909 distinct human disease genes have close homologues in fruitflies, the researchers scribbled the gene names and their corresponding syndromes on cards and handed them to a pathologist, who dutifully placed them into piles according to the nature of the disorder. This evolved into Homophila, a site where human disease genes and their fly homologues can be searched according to keyword, human disease name, gene name or OMIM entry number. For instance, typing in 'hypertension' leads to a results table showing, on the left, a description of the human disorder, the human gene symbol (for example, for the angiotensin II receptor) and related online references; on the right, the Drosophila protein sequence matches. In case you're daunted by the prospect of trundling through fruitfly data, a link from the fly gene of interest to GadFly (Genome Annotation Database of Drosophila) leads you to all that is known about the gene.

There's more to come, as the site curators promise a facility to match disease phenotypes that are common to humans and flies. As molecular signalling pathways are more completely described in flies compared with humans, human disease genes could be cloned on the basis of fly mutant phenotypes that are typical of a particular pathway. The site is updated monthly, so keep a lookout.