Isolation and characterization of a novel mycovirus infecting an edible mushroom,Grifola frondosa

Grifola frondosa (Maitake mushroom) is an important cultivated mushroom due to its medicinal and nutrient values. In this study, we isolated and characterized a novel partitivirus (named Grifola frondosa partitivirus 1, GfPV1) infecting a standard G. frondosa strain Gf-N2. This virus has a two-segmented dsRNA genome (dsRNA1 and dsRNA2) with nucleotide lengths of 2.3 and 2.2 kbp, respectively. The coding strand of dsRNA1 and dsRNA2 segments carries single open reading frame encoding RNA-dependent RNA polymerase (RdRp) and a coat protein (CP), respectively. BLAST searches and phylogenetic analyses showed that GfPV1 is most closely related to a betapartitivirus, Lentinula edodes partitivirus 1 (RdRp <70% and CP <60% amino acid sequence identities), but the sequence divergence suggests that GfPV1 is classifiable as a new member of the genus Betapartitivirus, family Partitiviridae. The presence of GfPV1 does not affect colony morphology and fruiting body development of G. frondosa. This is the first report investigating the effects of a mycovirus infection on the colony morphology and fruiting body development of G. frondosa. Interestingly, GfPV1 accumulations markedly decreased along with the fruiting body maturation stages, suggesting the inhibition of virus multiplication during sexual phase of the G. frondosa life cycle.     

Compilation of Japanese fisheries statistics for the Japanese eel, <Emphasis Type="Italic">Anguilla japonica</Emphasis>, since 1894: a historical dataset for stock assessment

Fishery sustainability and the extinction risk of the Japanese eel, Anguilla japonica, are of global concern. The landings of the Japanese eel in Japan comprise a large part of the landings in East Asia. This study provides a compiled dataset of the annual fisheries statistics of the Japanese eel in Japan for stock assessment. The Japanese government has been recording Japanese eel statistics annually since 1984 in five series of annual reports by conducting systematic questionnaire surveys of fisheries managers and associations; however, most of these data are stored in analog format. The key variables in the dataset include the harvest weight of eels, the harvest weight and number of seeds for aquaculture, the number of eels stocked, and the number of management entities engaged in the eel fishery. The levels of spatial aggregation of the variables include the site (river and lake), prefecture, inland and coastal waters, and total in Japan. We also incorporated location data (latitude and longitude) of the site and prefecture into the dataset. Eel harvest includes primarily yellow eels (late juvenile stage) and silver eels (mature stage). Seed harvest in inland waters includes glass eels (intermediate stage between leptocephalus and elver) and elvers (early juvenile stage). Seed harvest from coastal waters comprises glass eels. This dataset provides information to assess long-term trends in the Japanese eel population.     

Isolation of New Tobacco Constituents, 8,9-Dihydro-8,9-dihydroxymegastigmatrienone,from Japanese Domestic Suifu Tobacco

The tetradecapeptide of a renin substrate, DRVYIHPFHLLVYS, was used as a substrate for assaying several fungal aspartic and acidic proteinases in the acidic pH range. Aspartic and acidic proteinases froll) Phycomycetes, Mucor and Rhizopus, and Deuteromycotina, Aspergillus and Penicillium, cleaved the tetradecapeptide at its tyrosyl⁴-isoleucyl⁵ (Y⁴-I⁵),histidyI⁶-proly⁷ (H⁶_P⁷) and leucyl¹¹-valyl¹² (L¹¹-V¹²) bonds in the acidic pH range, while acidic proteinases type B and type A-I from Scytalidium lignicolumn, and those from Cladosporium and Basidiomycetes, Pycnoporus sanguineus, and the yeast, Rhodotorula glutinis; showed slightly different specificities towards the tetradecapeptide. Pepsin primarily cleaved the valy³-tyrosyl⁴ (V³-Y⁴) and leucyl¹⁰-leucyl¹¹ (L¹⁰-L¹¹) bonds. All of the aspartic and acidic proteinases of fungal origin tested in the present study have different specificities from that of pepsin.     

AT1 receptor blocker azilsartan medoxomil normalizes plasma miR-146a and miR-342-3p in a murine heart failure model

Our study measured circulating microRNA (miRNA) levels in the plasma of calsequestrin (CSQ)-tg mouse, a severe heart failure model, and evaluated whether treatment with angiotensin II type 1 receptor blocker, azilsartan medoxomil (AZL-M) influenced their levels using miRNA array analysis. MiR-146a, miR-149, miR-150, and miR-342-3p were reproducibly reduced in the plasma of CSQ-tg mice. Among them, miR-146a and miR-342-3p were significantly restored by AZL-M, which were associated with improvement of survival rate and reduction of congestion. These results suggest that miRNA, especially miR-146a and miR-342-3p, could be used as potential biomarkers for evaluating the efficacy of anti-heart failure drugs.     

The Beta Cell in Its Cluster: Stochastic Graphs of Beta Cell Connectivity in the Islets of Langerhans

Pancreatic islets of Langerhans consist of endocrine cells, primarily α, β and δ cells, which secrete glucagon, insulin, and somatostatin, respectively, to regulate plasma glucose. β cells form irregular locally connected clusters within islets that act in concert to secrete insulin upon glucose stimulation. Due to the central functional significance of this local connectivity in the placement of β cells in an islet, it is important to characterize it quantitatively. However, quantification of the seemingly stochastic cytoarchitecture of β cells in an islet requires mathematical methods that can capture topological connectivity in the entire β-cell population in an islet. Graph theory provides such a framework. Using large-scale imaging data for thousands of islets containing hundreds of thousands of cells in human organ donor pancreata, we show that quantitative graph characteristics differ between control and type 2 diabetic islets. Further insight into the processes that shape and maintain this architecture is obtained by formulating a stochastic theory of β-cell rearrangement in whole islets, just as the normal equilibrium distribution of the Ornstein-Uhlenbeck process can be viewed as the result of the interplay between a random walk and a linear restoring force. Requiring that rearrangements maintain the observed quantitative topological graph characteristics strongly constrained possible processes. Our results suggest that β-cell rearrangement is dependent on its connectivity in order to maintain an optimal cluster size in both normal and T2D islets.     

Regulatory role of cardiolipin in the activity of an ATP-dependent protease, Lon, from Escherichia coli

Lon is an ATP-dependent serine protease that plays a significant role in the quality control of proteins in cells, degrading misfolded proteins and certain short-lived regulatory proteins under stresses as such heat-shock and UV irradiation. It is known that some polymers containing phosphate groups regulate enzymatic activity by binding with Lon. We focused on the phospholipids of biological membrane components such as phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and cardiolipin (CL), and examined whether or not liposomes containing these phospholipids regulate the enzymatic activity of Lon. CL-containing liposomes specifically inhibited both the proteolytic and ATPase activities of Lon in a dose-dependent manner. In addition, on pull-down assay, we found that CL-containing liposomes selectively bound to Lon. The interaction between CL-containing liposomes and Lon changed with the order of addition of Mg(2+)/ATP. When CL-containing liposomes were added after the addition of Mg(2+)/ATP to Lon, the binding of CL-containing liposomes to Lon was significantly decreased as compared with the reversed order. In fact, we found that CL-containing liposomes bound to Lon, resulting in inhibition of the enzymatic activity of Lon. These results suggest that Lon interacts with CL in biological membranes, which may regulate the functions of Lon as a protein-degrading centre in accordance with environmental changes inside cells.     

Evidence for genetically influenced caste determination in phylogenetically diverse species of the termite genus Reticulitermes

A number of social insect species have recently been shown to have genetically influenced caste determination (GCD), challenging the conventional view that caste determination should be strictly environmental. To date, GCD has been found in phylogenetically isolated species; examples of GCD being present in multiple species of a genus are lacking. Through crossing experiments of neotenic (juvenile) reproductives, we have recently provided the first evidence for a royal versus worker GCD in the termite Reticulitermes speratus. To elucidate whether this system is more widespread, we performed crossing experiments using three additional Reticulitermes species. Offspring caste and sex ratios were found to be highly similar to those found previously in R. speratus, raising the possibility that GCD was present in an ancestral lineage of Reticulitermes, and subsequently maintained throughout several episodes of speciation.     

Phytuberol,from Japanese Domestic Tobacco,Nicotiana tabacum cv. Suifu

Carcinogenesis is believed to be induced through the oxidative damage of DNA, and antioxidants are expected to suppress it. So, the polyphenolic antioxidants in daily foods were investigated to see whether they protect against genetic damage by active oxygen. In the evaluation, we used a bioassay and a chemical determination, a Salmonella mutagenicity test for mutation by a N-hydroxyl radical from one of the dietary carcinogens 3-amino-1-methyl-5H-pyrido[4,3-b]indole and the formation of 8-hydroxyl (8-OHdG) from 2′-deoxyguanosine (2′-dG) in a Fenton OH-radical generating system. Thirty-one antioxidants including flavonoids were compared in terms of radical-trapping activity with bacterial DNA and 2′-dG. Antioxidants inhibited the mutation but the IC₅₀ values were in the mM order. Against 8-OHdG formation, only α-tocopherol had a suppressive effect with an IC₅₀ of 1.5 μM. Thus, except α-tocopherol, the dietary antioxidants did not scavenge the biological radicals faster than bacterial DNA and intact 2′-dG, indicating that they failed to prevent oxidative gene damage and probably carcinogenesis.