A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/ GII.P17-GII.17, this variant has a newly identified GII. P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important. The present study uses complete genome sequences and phylogenetic and in silico analyses to characterise GII.P17 norovirus strains contributing to gastroenteritis outbreaks in Japan from December 2014 to March 2015.

Capsid protein of norovirus genogroup II (GII) plays crucial roles in host infection. Although studies on capsid gene evolution have been conducted for a few genotypes of norovirus, the molecular evolution of norovirus GII is not well understood. Here we report the molecular evolution of all GII genotypes, using various bioinformatics techniques. The time-scaled phylogenetic tree showed that the present GII strains diverged from GIV around 1630CE at a high evolutionary rate (around 10−3 substitutions/site/year), resulting in three lineages. The GII capsid gene had large pairwise distances (maximum > 0.39). The effective population sizes of the present GII strains were large (>102) for about 400 years. Positive (20) and negative (over 450) selection sites were estimated. Moreover, some linear and conformational B-cell epitopes were found in the deduced GII capsid protein. These results suggested that norovirus GII strains rapidly evolved with high divergence and adaptation to humans.

In the current studies, we sequenced and characterized the gene for the homeodomain protein (hox1) in a bipolar mushroom, Pholiota nameko, which is a putative homologue of A mating type genes in the tetrapolar basidiomycete, Coprinopsis cinerea. We also sequenced and characterized the gene for the pheromone receptor (rcb1) in P. nameko, which is a putative homologue of the B mating type genes in C. cinerea. Restriction fragment length polymorphism (RFLP) and linkage analyses indicated that the both genes are present as a single locus on the different chromosome. Moreover, in P. nameko, the hox1 gene was mapped to the A mating type locus in linkage group I. However, rcb1 was not linked to the A mating type locus and was mapped to the other linkage group. These results strongly suggest that hox1 regulates with incompatibility in the bipolar mushroom, and that rcb1 may not affect the mating function in P. nameko. This is the first report regarding the structure of the mating type genes in bipolar mushrooms.

A recombinant norovirus, GII.P16-GII.4_Sydney2012, was first detected from nine patients with gastroenteritis in Kawasaki City, Japan, in 2016. The viral genome showed nucleotide sequence identities of 95.1% and 97.2% to the closest strains in the regions of 5′ terminus to ORF1 and ORF2 to 3′ terminus, respectively.

The RNA-dependent RNA polymerase (RdRp) and capsid (VP1) genes of 51 GII.2 human norovirus (HuNoV) strains collected during the period of 2004–2015 in Japan were analyzed. Full-length analyses of the genes were performed using next-generation sequencing. Based on the gene sequences, we constructed the time-scale evolutionary trees by Bayesian Markov chain Monte Carlo methods. Time-scale phylogenies showed that the RdRp and VP1 genes evolved uniquely and independently. Four genotypes of GII.2 (major types: GII.P2-GII.2 and GII.P16-GII.2) were detected. A common ancestor of the GII.2 VP1 gene existed until about 1956. The evolutionary rates of the genes were high (over 10−3 substitutions/site/year). Moreover, the VP1 gene evolution may depend on the RdRp gene. Based on these results, we hypothesized that transfer of the RdRp gene accelerated the VP1 gene evolution of HuNoV genotype GII.2. Consequently, recombination between ORF1 (polymerase) and ORF2 (capsid) might promote changes of GII.2 antigenicity.

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/J-/V-Acetylhexosaminidase (EC 3.2.1.52) from the culture filtrate of Nocardia orientalis was purified to homogeneity by precipitation with ammonium sulfate followed by column chromatography on CM-Sephadex, Bio-Gel P-60, and phenyl-Sepharose CL-4B. The molecular weight of the enzyme was about 56,000 by gel filtration and 54,000 by SDSpolyacrylamide gel electrophoresis. The enzyme showed about 1.6-fold higher j?-/V-acetylglucosaminidase activity than /?-/V-acetyIgaIactosaminidase activity. The optimum pH and temperature were 5.0 and around 70-75 C for PNP-GlcNAc, and 4.0 and 60 C for PNP-GalNAc. The enzyme was stable in the pH range from 4.0 to 8.0 and below 45 C.The enzyme hydrolyzed /V-acetyl-chitooligosaccharides, di-7V-acetyl-chitobiose through hexa-/Vacetyl-chitohexaose. The enzyme showed glycosyl transferase activity during the hydrolysis of di-/Vacetyl-chitobiose.Twomajor transfer products were isolated and identified as the /Hl-»6)-linked disaccharide of N-acetylglucosamine and tri-/V-acetyl-chitotriose.jS-iV-Acetylhexosaminidase (EC 3.2.

We cloned a gene encoding the succinate dehydrogenase iron-sulfur protein subunit (sip) from a bipolar mushroom, Pholiota microspora, and introduced a point mutation that confers carboxin resistance into this gene. Using this homologous selective marker and also a heterologous drug selective marker, the hygromycin B phosphotransferase gene (hph), we successfully constructed a DNA-mediated transformation system in P. microspora. Both these selection markers have high transformation efficiency: the effi ciency of carboxin resistance transformation was about 88.8 transformants/μg pMBsip2 DNA using 5 × 10 6 protoplasts in regeneration plates containing 1.0 μg/ml carboxin, and the effi ciency of hygromycin B resistance transformation was about 122.4 transformants/μg pMBhph1 DNA using 5 × 10 6 protoplasts in regeneration plates containing 150 μg/ml hygromycin B. Southern hybridization analysis showed that the introduced sequence (mutant sip or hph) was integrated into the chromosomal DNA in these transformants with a copy number of one or more.