Eutrophication of mountain lakes in Japan due to increasing deposition of anthropogenically produced dust

Atmospheric dust has wide-reaching effects, not only influencing climate conditions, but also ecosystems. The eastern region of the Asian continent is one of the largest emitters of dust in the world, and recent economic growth in the region has been accompanied by an increase in anthropogenic emissions. However, the effects of increased Asian dusts on aquatic ecosystems are not well understood. We examined fossil pigments and zooplankton remains from ²¹⁰Pb-dated sediments taken from high mountain lakes of Hourai-Numa and Hachiman-Numa, located in the Towada-Hachimantai National Park of Japan Islands, to uncover historical changes in the phyto- and zooplankton community over the past 100?years. Simultaneously, we measured the geochemical variables of TOC, TN, TP, ??¹³C, ??¹⁵N, and lead isotopes (²⁰⁷Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁶Pb) in the sediments to identify environmental factors causing such changes. As a result, despite few anthropogenic activities in the watersheds, alpine lakes in Japan had increased algal and herbivore plankton biomasses by 3?C6 fold for recent years depending on the surrounding terrestrial vegetation and landscape conditions. Biological and biogeochemical proxies recorded from the lake sediments showed that this eutrophication occurred after the 1990s when P deposition increased as a result of atmospheric loading of dust transported from the Asian continent. The continued increase of anthropogenically produced dust may therefore impart damaging impacts on mountain ecosystems even if they are protected from direct anthropogenic disturbances.     

ABCG2/BCRP Dysfunction as a Major Cause of Gout

Recent genome-wide association studies showed that serum uric acid (SUA) levels relate to ABCG2/BCRP gene, which locates in a gout-susceptibility locus revealed by a genome-wide linkage study. Together with the ABCG2 characteristics, we hypothesized that ABCG2 transports urate and its dysfunction causes hyperuricemia and gout. Transport assays showed ATP-dependent transport of urate via ABCG2. Kinetic analysis revealed that ABCG2 mediates high-capacity transport of urate (Km: 8.24 ± 1.44 mM) even under high-urate conditions. Mutation analysis of ABCG2 in 90 Japanese hyperuricemia patients detected six nonsynonymous mutations, including five dysfunctional variants. Two relatively frequent dysfunctional variants, Q126X and Q141K, were then examined. Quantitative trait locus analysis of 739 Japanese individuals showed that Q141K increased SUA as the number of minor alleles of Q141K increased (p = 6.60 × 10^?5). Haplotype frequency analysis revealed that there is no simultaneous presence of Q126X and Q141K in one haplotype. Becuase Q126X and Q141K are assigned to nonfunctional and half-functional haplotypes, respectively, their genotype combinations are divided into four functional groups. The association study with 161 male gout patients and 865 male controls showed that all of those with dysfunctional ABCG2 increased the gout risk, especially those with ≤1/4 function (OR, 25.8; 95% CI, 10.3–64.6; p = 3.39 × 10^?21). These genotypes were found in 10.1% of gout patients, but in only 0.9% of control. Our function-based clinicogenetic (FBCG) analysis showed that combinations of the two dysfunctional variants are major causes of gout, thereby providing a new approach for prevention and treatment of the gout high-risk population.     

Carbenoxolone Disodium Treatment for Canine Pituitary-Dependent Hyperadrenocorticism

Pituitary-dependent hyperadrenocorticism (PDH) is mainly caused by pituitary corticotroph tumors in dogs. A characteristic feature of corticotroph tumors is their resistance to negative feedback by glucocorticoids. In some animal species, including dogs, the aberrant expression of 11β-hydroxysteroid dehydrogenase (11HSD), a cortisol metabolic enzyme, is observed in corticotroph tumors. We previously reported that carbenoxolone (CBX), an inhibitor of 11HSD, suppressed ACTH secretion from the pituitary gland, and decreased cortisol concentrations in healthy dogs. Therefore, the aim of this study was to investigate the therapeutic effects of CBX on dogs with PDH. Six dogs with PDH were treated with 60 to 80 mg/kg/day of CBX for 6 weeks, followed by trilostane, which is a commonly used agent for canine PDH. CBX treatment led to a gradual decrease in both basal and in corticotropic releasing hormone (CRH)-stimulated plasma ACTH concentrations and CRH-stimulated serum cortisol concentrations, without side effects. However, basal and stimulated ACTH and cortisol concentrations remained higher than those of healthy dogs, and clinical symptoms such as polydipsia and polyuria were not ameliorated. After a 2-week wash-out interval, trilostane was administered for 2 weeks. Although basal plasma ACTH concentrations were higher after trilostane treatment than CBX treatment, polydipsia and polyuria resolved in all six dogs. The reason for the lack of improvement in polydipsia and polyuria with CBX treatment is unclear. Other mechanisms, in addition to a partial decrease in ACTH secretion, are likely to be involved. In conclusion, this is the first study to report the in vivo effects of CBX in dogs with PDH. The findings suggest that CBX inhibits ACTH secretion from canine pituitary tumors, resulting in lower cortisol concentrations.     

Effects of Adding Alkaline Material on the Heavy Metal Chemical Fractions in Soil under Flooded and Non-Flooded Conditions

We investigated the effect of adding an alkaline material (containing calcium carbonate and gypsum) on the immobilization of heavy metals (Cd, Cu, Pb, and Zn) in a paddy soil slightly contaminated with Cd and Zn under flooded and non-flooded conditions in the laboratory. Adding the alkaline material increased the soil pH and significantly decreased the exchangeable fraction of all of the metals, especially for Cd (>75% decrease) and Zn (ca. 90% decrease), under both flooded and non-flooded conditions. Drying the flooded soil samples increased the ratio of exchangeable fraction to the total fraction, particularly for Cd. The exchangeable fraction ratio was lower in the dried, previously flooded samples that contained the alkaline material than in the samples that did not contain the alkaline material, indicating that adding the alkaline material would be an effective way of immobilizing heavy metals during the oxidation of anoxic soils. These results show that the alkaline material can be used to immobilize heavy metals under both anoxic and oxic conditions, and that the effects of flooding and amending a paddy soil with alkaline material on the chemical forms will be different between heavy metals.     

Cystatin 10, a novel chondrocyte-specific protein,may promote the last steps of the chondrocyte differentiation pathway

This study attempts to characterize cystatin 10 (Cst10), which we recently identified as a novel protein implicated in endochondral ossification. Expression of Cst10 was specific to cartilage, localized in the cytosol of prehypertrophic and hypertrophic chondrocytes of the mouse growth plate. In the mouse chondrogenic cell line ATDC5, Cst10 expression preceded type X collagen expression and increased in synchrony with maturation. When we compared ATDC5 cells transfected with Cst10 cDNA with cells transfected with a mock vector, hypertrophic maturation and mineralization of chondrocytes were promoted by Cst10 gene overexpression in that type X collagen expression was observed earlier, and alizarin red staining was stronger. On the other hand, type II collagen expression and Alcian blue staining, both of which are markers of the early stage of chondrocyte differentiation, were similar in both cells. Overexpression of the Cst10 gene also caused fragmentation of nuclei, the appearance of annexin V, a change in the mitochondrial membrane potential, and activation of caspases. These results strongly suggest that Cst10 may play an important role in the last steps of the chondrocyte differentiation pathway as an inducer of maturation, followed by apoptosis of chondrocytes.     

Molecular cloning and functional expression of nucleolar phospholipid hydroperoxide glutathione peroxidase in mammalian cells

We cloned a full-length cDNA for phospholipid hydroperoxide glutathione peroxidase (PHGPx) including exon Ib from rat and mouse testis. The nuclear signal sequence of the N terminal of rat nuclear PHGPx possessed a different sequence from that previously reported for rat sperm nuclei GPx (SnGPx). Expression of this PHGPx-YFP (yellow fluorescent protein) fusion protein including a novel nuclear signal sequence was exclusively localized in nucleolus; although YFPs fused with only a novel nuclear signal sequence were distributed in the whole nucleus, indicating that preferential translocation of nucleolar PHGPx into nucleoli was required for the nuclear signal sequence and internal sequence of PHGPx. Low level expression of nucleolar PHGPx was detected in several tissues, but the expression of nucleolar PHGPx was extensively high in testis. Immunohistochemical analysis with anti-nucleolar PHGPx indicated that expression of nucleolar PHGPx was observed in the nucleoli in the spermatogonia, spermatocyte, and spermatid. Overexpression of 34kDa nucleolar PHGPx in RBL2H3 cells significantly suppressed cell death induced by actinomycin D and doxorubicin that induced damage in the nucleolus. These results indicated that nucleolar PHGPx plays an important role in prevention of nucleolus from damage in mammalian cells.     

Synthesis of p-nitrophenyl sulfated disaccharides with beta-D-(6-sulfo)-GlcNAc units using beta-N-acetylhexosaminidase from Aspergillus oryzae in a transglycosylation reaction

When α-d-GlcNAc-OC₆H₄NO₂ -p and β-d-(6-sulfo)-GlcNAc-OC₆H₄NO₂-p (2) were used as substrates, β-N-acetylhexosaminidase from Aspergillus oryzae transferred the β-d-(6-sulfo)-GlcNAc(unit from 2 to α-d-GlcNAc-OC₆H₄NO₂ -p to afford β-d-(6-sulfo)-GlcNAc-(1→4)-α-d-GlcNAc-OC₆H₄NO₂-p (3) in a yield of 94% based on the amount of donor, 2, added. β-d-(6-sulfo)-GlcNAc-(1→4)-α-d-Glc-OC₆H₄NO₂-p (4) was obtained with α-d-Glc-OC₆H₄NO₂ -p as acceptor in a similar manner. With a reaction mixture of 2 and β-d-GlcNAc-OC₆H₄NO₂-p (1) in a molar ratio of 6:1, the enzyme mediated the transfer of β-d-GlcNAc from 1 to 2, affording disaccharide β-d-GlcNAc-(1→4)-β-(6-sulfo)-d-GlcNAc-OC₆H₄NO₂-p (5) in a yield of 13% based on the amount of 1 added.     

Catecholamine-containing pancreatic islet cells of the domestic fowl

Summary In an attempt to identify pancreatic islet cells emitting formaldehyde-induced fluorescence (FIF), the pancreatic islets of the domestic fowl were studied by combined fluorescence, ultrastructural, silver-impregnation and immunohistochemical methods in the same section or in consecutive semi-thin and ultra-thin sections. The results indicate that islet cells emitting intense FIF exhibit a strongly argyrophil reaction with the Grimelius' silver method and also immunohistochemical reaction with anti-glucagon serum, but not with anti-5-HT serum. Therefore, the fowl islet A cell, a peptide hormone-producing cell, stores simultaneously catecholamine as biogenic amine. The islet B and D cells did not display any FIF, any argyrophil reaction with the Grimelius' silver method, or any immunoreactivity with anti-glucagon or anti-5-HT sera. The fluorescent but non-argyrophil cells dispersed in the exocrine acinus may well be PP cells.     

An NB-LRR gene, <Emphasis Type="Italic">TYNBS1</Emphasis>, is responsible for resistance mediated by the <Emphasis Type="Italic">Ty</Emphasis>-<Emphasis Type="Italic">2 Begomovirus</Emphasis> resistance locus of tomato

Key message

An NB-LRR gene, TYNBS1, was isolated from Begomovirus-resistance locus Ty-2. Transgenic plant analysis revealed that TYNBS1 is a functional resistance gene. TYNBS1 is considered to be synonymous with Ty-2.

Abstract

Tomato yellow leaf curl disease caused by Tomato yellow leaf curl virus (TYLCV) is a serious threat to tomato (Solanum lycopersicum L.) production worldwide. A Begomovirus resistance gene, Ty-2, was introduced into cultivated tomato from Solanum habrochaites by interspecific crossing. To identify the Ty-2 gene, we performed genetic analysis. Identification of recombinant line 3701 confirmed the occurrence of a chromosome inversion in the Ty-2 region of the resistant haplotype. Genetic analysis revealed that the Ty-2 gene is linked to an introgression encompassing two markers, SL11_25_54277 and repeat A (approximately 200 kb). Genomic sequences of the upper and lower border of the inversion section of susceptible and resistant haplotypes were determined. Two nucleotide-binding domain and leucine-rich repeat-containing (NB-LRR) genes, TYNBS1 and TYNBS2, were identified around the upper and lower ends of the inversion section, respectively. TYNBS1 strictly co-segregated with TYLCV resistance, whereas TYNBS2 did not. Genetic introduction of genomic fragments containing the TYNBS1 gene into susceptible tomato plants conferred TYLCV resistance. These results demonstrate that TYNBS1 is a functional resistance gene for TYLCV, and is synonymous with the Ty-2 gene.