Despite the availability of the genome sequences of filmentous fungi, such as Neurospora crassa and Aspergillus nidulans, a comprehensive analysis of their sugar transport systems has not yet been made. In this work we have identified a glucose transporter gene family of the filamentous fungus Trichoderma reesei based on the analysis of a draft version of the genome sequence, which was made publicly available by the DOE Joint Genome Institute. We began by screening the JGI-predicted genes in a search for genes displaying carbohydrate transporter activity. As most of the sequences had not been manually annotated, we used the available EST sequences of T. reesei to improve the annotation of the genes. Topology prediction of transmembrane helices was evaluated with the program TMHMM. Proteins with less than 8 predicted transmembrane domains were not considered for further analyses, since sugar transporter genes of the Major Facilitator Superfamily (MFS) of transporters are characterized by 12 transmembrane spanning segments. Several other characteristic motifs found in members of the MFS were also identified. Comparison of the glucose transporters of T. reesei and other microorganisms by phylogenetic analyses is underway. The pattern of expression of the genes on different glucose concentrations is also being analyzed. This work may contribute a better understanding of the sugar transport systems developed by microorganisms, such as T. reesei, adapted to nutrient-poor environments.

Financial support: FAPESP