Annotation and analysis of the geome of Phycomyces blakesleeanus, a model photoresponsive zygomycete
Light induces in P. blakesleeanus multiple developmental and biochemical responses (sporangiophore growth and development, beta-carotene synthesis). P. blakesleeanus is an intensively studied, experimentally tractable model organism, and whole-genome analysis is expected to further elucidate the signaling pathways underlying its photoregulation. To this end, the genome was sequenced to 7.49X depth and assembled into 475 scaffolds totaling 56Mbp, and 47847 ESTs were assembled from cDNAs of light and dark cultures. We combined into a single annotation pipeline a variety of gene modeling methods (homology-based, EST-based, and ab initio), and predicted 14792 protein-coding genes. Many of these gene predictions are supported by homology in nr (68percent), by Pfam domains (44percent), or by ESTs (35percent). We next assigned GO terms to 41percent of the proteins and EC numbers to 16percent. We then distributed these annotations to the Phycomyces consortium, along with tools to curate them manually. We expect that the annotation will provide a solid platform for expression analysis. In addition to its value as a model organism, P. blakesleeanus is the second zygomycete with a sequenced genome, after the related Rhizopus oryzae. We therefore will present preliminary results of comparative analysis between the two zygomycetes.