The mushroom Coprinopsis cinerea is a classic experimental model for multicellular development in fungi because it grows on defined media, completes its life cycle in 2 weeks, produces some 10 8 synchronized meiocytes, and can be manipulated at all stages in development by mutation and transformation. The 37-megabase genome of C. cinerea was sequenced and assembled into 13 chromosomes. Meiotic recombination rates vary greatly along the chromosomes, and retrotransposons are absent in large regions of the genome with low levels of meiotic recombination. Single-copy genes with identifiable orthologs in other basidiomycetes are predominant in low-recombination regions of the chromosome. In contrast, paralogous multicopy genes are found in the highly recombining regions, including a large family of protein kinases (FunK1) unique to multicellular fungi. Analyses of P450 and hydrophobin gene families confirmed that local gene duplications drive the expansions of paralogous copies and the expansions occur in independent lineages of Agaricomycotina fungi. Gene-expression patterns from microarrays were used to dissect the transcriptional program of dikaryon formation (mating). Several members of the FunK1 kinase family are differentially regulated during sexual morphogenesis, and coordinate regulation of adjacent duplications is rare. The genomes of C. cinerea and Laccaria bicolor , a symbiotic basidiomycete, share extensive regions of synteny. The largest syntenic blocks occur in regions with low meiotic recombination rates, no transposable elements, and tight gene spacing, where orthologous single-copy genes are overrepresented. The chromosome assembly of C. cinerea is an essential resource in understanding the evolution of multicellularity in the fungi.

The basidiomycete fungus Coprinopsis cinerea is an important model system for multicellular development. Fruiting bodies of C. cinerea are typical mushrooms, which can be produced synchronously on defined media in the laboratory. To investigate the transcriptome in detail during fruiting body development, high-throughput sequencing (RNA-seq) was performed using cDNA libraries strand-specifically constructed from 13 points (stages/tissues) with two biological replicates. The reads were aligned to 14,245 predicted transcripts, and counted for forward and reverse transcripts. Differentially expressed genes (DEGs) between two adjacent points and between vegetative mycelium and each point were detected by Tag Count Comparison (TCC). To validate RNA-seq data, expression levels of selected genes were compared using RPKM values in RNA-seq data and qRT-PCR data, and DEGs detected in microarray data were examined in MA plots of RNA-seq data by TCC. We discuss events deduced from GO analysis of DEGs. In addition, we uncovered both transcription factor candidates and antisense transcripts that are likely to be involved in developmental regulation for fruiting.

The homobasidiomycete Coprinus cinereus exhibits remarkable photomorphogenesis during fruiting-body development. Under proper light conditions, fruiting-body primordia proceed to the maturation phase in which basidia in the pileus undergo meiosis, producing sexual spores, followed by stipe elongation and pileus expansion for efficient dispersal of the spores. In the continuous darkness, however, the primordia do not proceed to the maturation phase but are etiolated: the pileus and stipe tissues at the upper part of the primordium remain rudimentary and the basal part of the primordium elongates, producing ''dark stipe.'' In this study we genetically analyzed five strains that produce dark stipes even if light conditions promoting the maturation are given and then characterized one of them, Uar801 (dst1-1). The dst1 gene was cloned as a DNA fragment that rescues the dst1-1 mutation. Dst1 is predicted to be a protein of 1175 amino acids that contains two PAS domains, a coiled-coil structure, and a putative, glutamine-rich, transcriptional activation domain (AD). One of the PAS domains exhibits significant similarity to the LOV domains of known bluelight receptors, suggesting that Dst1 is a blue-light receptor of C. cinereus. The dst1-1 mutation is predicted to truncate the putative AD in the C-terminal region.

No abstract

No abstract