Expressed sequences tags of the anther smut fungus, Microbotryum violaceum, identify mating and pathogenicity genes
1 UMR 8079 CNRS-UPS, Ecologie, Systématique et Evolution, Bâtiment 360, Université Paris-Sud, F-91405 Orsay Cedex, France
2 UMR 5202, CNRS-MNHN, Origine, Structure et Evolution de la Biodiversité, Département Systématique et Evolution, 16 rue Buffon CP 39, 75005, Paris, France
3 INRA, Unité Mathématique, Informatique et Génome, Domaine Vilvert, Jouy-en-Josas, F-78352, France
4 Department of Biology, Amherst College, Amherst, MA 01002, USA
5 Génoscope, UMR CNRS 8030, 2 Gaston Crémieux, CP 5706, 91507 Evry, France
BMC Genomics 2007, 8:272 doi:10.1186/1471-2164-8-272Published: 10 August 2007
The basidiomycete fungus Microbotryum violaceum is responsible for the anther-smut disease in many plants of the Caryophyllaceae family and is a model in genetics and evolutionary biology. Infection is initiated by dikaryotic hyphae produced after the conjugation of two haploid sporidia of opposite mating type. This study describes M. violaceum ESTs corresponding to nuclear genes expressed during conjugation and early hyphal production.
A normalized cDNA library generated 24,128 sequences, which were assembled into 7,765 unique genes; 25.2% of them displayed significant similarity to annotated proteins from other organisms, 74.3% a weak similarity to the same set of known proteins, and 0.5% were orphans. We identified putative pheromone receptors and genes that in other fungi are involved in the mating process. We also identified many sequences similar to genes known to be involved in pathogenicity in other fungi. The M. violaceum EST database, MICROBASE, is available on the Web and provides access to the sequences, assembled contigs, annotations and programs to compare similarities against MICROBASE.
This study provides a basis for cloning the mating type locus, for further investigation of pathogenicity genes in the anther smut fungi, and for comparative genomics.