GENE DISCOVERY THROUGH EXPRESSED SEQUENCE TAG SEQUENCING IN TRYPANOSOMA-CRUZI

Analysis of expressed sequence tags (ESTs) constitutes a useful approa ch for gene identification that, in the case of human pathogens, might result in the identification of new targets for chemotherapy and vacc ine development. As part of the Trypanosoma cruzi genome project, we h ave partially sequenced the 5' ends of 1,949 clones to generate ESTs, The clones were randomly selected from a normalized CL Brener epimasti gote cDNA library. A total of 14.6% of the clones were homologous to p reviously identified T. cruzi genes, while 18.4% had significant match es to genes from other organisms in the database. A total of 67% of th e ESTs had no matches in the database, and thus, some of them might be T. cruzi-specific genes. Functional groups of those sequences with ma tches in the database were constructed according to their putative bio logical functions, The two largest categories were protein synthesis ( 23.3%) and cell surface molecules (10.8%). The information reported in this paper should be useful for researchers in the field to analyze g enes and proteins of their own interest.