An ordered collection of expressed sequences from Cryphonectria parasitica and evidence of genomic microsynteny with Neurospora crassa and Magnaporthe grisea

Center for Biosystems Research, University of Maryland Biotechnology Institute, 5115 Plant Sciences Building, College Park, MD 20742, USA Correspondence Donald L. Nuss nuss{at}umbi.umd.edu Cryphonectria parasitica , the causative agent of chestnut blight, has proven to be a tractable experimental system for studying fungal pathogenesis. Moreover, the development of infectious cDNA clones of C. parasitica hypoviruses, capable of attenuating fungal virulence, has provided the opportunity to examine molecular aspects of fungal plant pathogenesis in the context of biological control. In order to establish a genomic base for future studies of C. parasitica , the authors have analysed a collection of expressed sequences. A mixed cDNA library was prepared from RNA isolated from wild-type (virus-free) and hypovirus-infected C. parasitica strains. Plasmid DNA was recovered from individual transformants and sequenced from the 5' end of the insert. Contig analysis of the collected sequences revealed that they represented approximately 2200 individual ORFs. An assessment of functional diversity present in this collection was achieved by using the BLAST software utilities and the NCBI protein database. Candidate genes were identified with significant potential relevance to C. parasitica growth, development, pathogenesis and vegetative incompatibility. Additional investigations of a 12·9 kbp genomic region revealed microsynteny between C. parasitica and both Neurospora cras sa and Magnaporthe grisea , two closely related fungi. These data represent the largest collection of sequence information currently available for C. parasitica and are now forming the basis of further studies using microarray analyses to determine global changes in transcription that occur in response to hypovirus infection. Abbreviations: EST, expressed sequence tag; GO, gene ontology The GenBank accession numbers for the sequences determined in this work are CB686454 – CB690670 . Tables of clones classified according to molecular function and biological process are available as supplementary data with the online version of this paper at http://mic.sgmjournals.org. Present address: Children's National Medical Center, Center for Genetic Medicine, 111 Michigan Avenue NW, Washington DC 20010, USA. Present address: Department of Molecular Biology, Keio University School of Medicine, 144 : 8 Ogura, Saiwai, Kawasaki, Kanagawa 212-0054, Japan. Present address: Biotechnology Research Center, Guangxi Univer