The filamentous fungus Trichoderma reesei produces and secretes profuse quantities of enzymes that act synergistically to degrade cellulase and related biomass components. We partially sequenced over 5100 random T. reesei cDNA clones. Among the sequences whose predicted gene products had significant similarity to known proteins, 12 were identified that encode previously unknown enzymes that likely function in biomass degradation. Microarrays were used to query the expression levels of each of the sequences under different conditions known to induce cellulolytic enzyme synthesis. Most of the genes encoding known and putative biomass-degrading enzymes were transcriptionally coregulated. Moreover, despite the fact that several of these enzymes are not thought to degrade cellulase directly, they were coordinately overexpressed in a cellulase overproducing strain. A variety of additional sequences whose function could not be ascribed using the limited sequence available displayed analogous behavior and may also play a role in biomass degradation or in the synthesis of biomass-degrading enzymes. Sequences exhibiting additional regulatory patterns were observed that might reflect roles in regulation of cellulase biosynthesis. However, genes whose products are involved in protein processing and secretion were not highly regulated during cellulase induction.
Analysis of the Magnaporthe oryzae chromosome 7 and comparison with syntenic regions in other fungal genomes suggests that transposable elements create localized segments with increased rates of chromosomal rearrangements, gene duplications and gene evolution.
Here we report the genome sequence of the lesion nematode, Pratylenchus coffeae, a significant pest of banana and other staple crops in tropical and sub-tropical regions worldwide. Initial analysis of the 19.67 Mb genome reveals 6712 protein encoding genes, the smallest number found in a metazoan, although sufficient to make a nematode. Significantly, no developmental or physiological pathways are obviously missing when compared to the model free-living nematode Caenorhabditis elegans, which possesses approximately 21 000 genes. The highly streamlined P. coffeae genome may reveal a remarkable functional plasticity in nematode genomes and may also indicate evolutionary routes to increased specialisation in other nematode genera. In addition, the P. coffeae genome may begin to reveal the core set of genes necessary to make a multicellular animal. Nematodes exhibit striking diversity in the niches they occupy, and the sequence of P. coffeae is a tool to begin to unravel the mechanisms that enable the extraordinary success of this phylum as both free-living and parasitic forms. Unlike the sedentary endoparasitic root-knot nematodes (Meloidogyne spp.), P. coffeae is a root-lesion nematode that does not establish a feeding site within the root. Because the P. coffeae nematode genome encodes fewer than half the number of genes found in the genomes of root-knot nematodes, comparative analysis to determine genes P. coffeae does not carry may help to define development of more sophisticated forms of nematode-plant interactions. The P. coffeae genome sequence may help to define timelines related to evolution of parasitism amongst nematodes. The genome of P. coffeae is a significant new tool to understand not only nematode evolution but animal biology in general.
Trichoderma reesei is a filamentous fungus widely used as an efficient protein producer and known to secrete large quantities of biomass degrading enzymes. Much work has been done aimed at improving the secretion efficiency of this fungus. It is generally accepted that the major bottlenecks in secretion are protein folding and ornamentation steps in this pathway. In an attempt to identify genes involved in these steps, the 5P ends of 21 888 cDNA clones were sequenced from which a unique set of over 5000 were also 3P sequenced. Using annotation tools Gene Ontology terms were assigned to 2732 of the sequences. Homologs to the majority of Aspergillus niger's Srg genes as well as a number of homologs to genes involved in protein folding and ornamentation pathways were identified.
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