Gene expression during Ustilago maydis diploid filamentous growth: Functional and comparative 'expressed sequence tag' analyses

Ustilago maydis is an important model organism for the plant pathogenic smut and rust fungi. These groups of fungi require an in planta growth phase for the completion of their life cycle. The evolution of this growth phase likely involved adaptations in form, physiology and/or timing of developmental processes. In this context it is important to identify genes present in U. maydis and those expressed during a developmental phase associated with in planta growth. I created two cDNA libraries from a forced diploid culture of U. maydis growing as filaments. From a combined library. 7455 ESTs were generated and assembled into 3074 contiguous sequences. This represents as much as 46% of the coding capacity predicted for U. maydis. BLAST similarity searches allowed me to annotate 59% of the contigs. Functional categorization and comparative analyses of the sequences provides gene identities, expression information and a solid base for future research.