Volvariella volvacea, the edible straw mushroom, is a highly nutritious food source that is widely cultivated on a commercial scale in many parts of Asia using agricultural wastes (rice straw, cotton wastes) as growth substrates. However, developments in V. volvacea cultivation have been limited due to a low biological efficiency (i.e. conversion of growth substrate to mushroom fruit bodies), sensitivity to low temperatures, and an unclear sexuality pattern that has restricted the breeding of improved strains. We have now sequenced the genome of V. volvacea and assembled it into 62 scaffolds with a total genome size of 35.7 megabases (Mb), containing 11,084 predicted gene models. Comparative analyses were performed with the model species in basidiomycete on mating type system, carbohydrate active enzymes, and fungal oxidative lignin enzymes. We also studied transcriptional regulation of the response to low temperature (4°C). We found that the genome of V. volvacea has many genes that code for enzymes, which are involved in the degradation of cellulose, hemicellulose, and pectin. The molecular genetics of the mating type system in V. volvacea was also found to be similar to the bipolar system in basidiomycetes, suggesting that it is secondary homothallism. Sensitivity to low temperatures could be due to the lack of the initiation of the biosynthesis of unsaturated fatty acids, trehalose and glycogen biosyntheses in this mushroom. Genome sequencing of V. volvacea has improved our understanding of the biological characteristics related to the degradation of the cultivating compost consisting of agricultural waste, the sexual reproduction mechanism, and the sensitivity to low temperatures at the molecular level which in turn will enable us to increase the industrial production of this mushroom.

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Patients with ulcerative colitis are at a very high risk of developing colorectal cancer. Corticotrophin-releasing hormone (CRH) family peptides and their receptors (CRHRs) are found to modulate inflammation and tumor cell growth. However, the role of CRH family peptides and their receptors in the inflammation-related colon cancer is still unknown. The aim of this study was to investigate the functions of CRHR1 signaling on the development of colitis-associated cancer (CAC). Crhr1-deficient (Crhr1 K/K ) mice were used to explore the role of CRHR1 in the development of azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced CAC. WT (Crhr1 C/C ) littermates were set as control. We found that the expression of CRHR1 and its endogenous ligands: urocortin and CRH were enhanced in the colon of Crhr1 C/C mice during treatment with AOM and DSS. Tumorigenesis was significantly reduced in Crhr1 K/K mice, determined by analysis of survival rate (increased by 20%), weight loss (decreased by 10%), tumor formation (decreased by 60% in tumor number), histological scores (decreased by 58%), and cytokine production. During early CAC tumorigenesis, Crhr1 K/K mice exhibited much less tumorigenesis, accompanied by lower inflammatory response, including decreased IL1b, IL6 and TNFa expression and macrophage infiltration and increased IL10 expression. Moreover, Crhr1 K/K mice displayed a reduced activation of NFkB and STAT3 phosphorylation with decreased proliferating and enhanced apoptotic cells in the colon. In conclusion, CRHR1 has a proinflammatory and therefore a protumorigenesis effect in terms of CAC, which may be helpful to develop new therapeutic approaches for inflammation and cancer prevention and treatment.

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