IDENTIFICATION AND MAPPING OF HUMAN CDNAS HOMOLOGOUS TO DROSOPHILA MUTANT-GENES THROUGH EST DATABASE SEARCHING

Cross-species comparison is an effective tool used to identify genes a nd study their function in both normal and pathological conditions. We have applied the power of Drosophila genetics to the vast resource of human cDNAs represented in the expressed sequence tag (EST) database (dbEST) to identify novel human genes of high biological interest. Six ty-six human cDNAs showing significant homology to genes causing Droso phila mutant phenotypes were identified by screening dbEST using the ' text string' option, and their map position was determined using both fluorescence in situ hybridization (FISH) and radiation hybrid mapping . Comparison between these genes and their putative partners in Drosop hila may provide important insights into their function in mammals. Fu rthermore, integration of these genes into the transcription map of th e human genome contributes to the positional candidate approach for di sease gene identification.