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991.
Toshiyuki Takai Akihiro Ohsumi Yumiko San-oh Ma. Rebecca C. Laza Motohiko Kondo Toshio Yamamoto Masahiro Yano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(7):1401-1410
Increasing leaf photosynthesis offers a possible way to improve yield potential in rice (Oryza sativa L.). Carbon isotope discrimination (Δ13C) has potential as an indirect selection criterion. In this study, we searched for quantitative trait loci (QTLs) controlling
Δ13C, and assessed their association with leaf photosynthesis. Substitution mapping by using chromosome segment substitution
lines (CSSLs), that carry segments from the indica cultivar Kasalath in the genetic background of the japonica cultivar Koshihikari, identified genomic regions affecting Δ13C on chromosomes (Chr.) 2, 3, 6, 7, and 12. One of the CSSLs, SL208, in which most regions on Chr. 3 were substituted with
Kasalath segments, showed higher leaf stomatal conductance for CO2 (g
s) and Δ13C than Koshihikari during the vegetative stage although leaf photosynthetic rate did not differ between them. These results
suggest an association between Δ13C and g
s. To test this association, we performed a QTL analysis for Δ13C at vegetative and heading stages in an F2 population derived from a cross between SL208 and Koshihikari. The results confirmed a QTL controlling Δ13C on the long arm of Chr. 3. By using a near-isogenic line specific to Hd6, we ruled out the possibility that variation in Δ13C was generated through the pleiotropic effect of heading date. 相似文献
992.
Minoru Suzuki Yoshinori Takahashi Satoru Nakano Tsuyoshi Abe Michio Masuda Toshiyuki Ohnishi Yoichi Noya Koh-ichi Seki 《Phytochemistry》2009,70(11-12):1410-1415
The production of labeled brominated metabolites with radioactive 82Br in Laurencia species was investigated as part of a study of the biosynthesis of halogenated metabolites from species belonging to the red algal genus Laurencia (Rhodomelaceae, Ceramiales). Radiobromide [82Br], thin-layer chromatography (TLC), and TLC–autoradioluminography (ARLG) were used. When cultured in artificial seawater medium (ASP12NTA including Na82Br) under 16:8 h light:dark (LD) illumination cycles for 24 h, each of the strains of Laurencia, Laurencia japonensis Abe et Masuda, Laurencia nipponica Yamada (laurencin-producing race and laureatin-producing race), and Laurencia okamurae Yamada, produced species- (or race-) specific 82Br-containing metabolites. In the case of the laurencin-producing race of L. nipponica, laurencin and deacetyllaurencin were found to be produced in approximately 1:1 ratio, though laurencin is the major metabolite in the wild sample. Furthermore, when cultured in the dark, the production rates of brominated metabolites in Laurencia spp. were found to be diminished. The present study strongly indicates that the use of radiobromine [82Br] in combination with the TLC–ARLG method is an effective approach for investigating the biosynthesis of brominated metabolites in Laurencia. 相似文献
993.
Juho Jakkila Matti Leppäranta Toshiyuki Kawamura Kunio Shirasawa Kalevi Salonen 《Aquatic Ecology》2009,43(3):681-692
Lake Pääjärvi, a boreal Finnish lake, was investigated in winter for weather conditions, structure and thickness of ice and snow, solar radiation, and under-ice current and temperature. Heat budget of Lake Pääjärvi in January–March was governed by terrestrial radiation losses of 20–35 W m?2 recompensed by ice growth of 0.5–1.0 cm day?1. In April, snow melted, albedo decreased from 0.8 to <0.1, and the mean ice melt rate was 1.5 cm day?1. Internal melting and surface melting were about equal. The mean turbulent heat loss was small. The heat flux from the water to ice was about 5 W m?2 in winter, increasing to 12 W m?2 in the melting season. The light attenuation coefficient was 1.1 m?1 for the congelation ice (black ice) in winter, compared with 1.5 m?1 for the lake water, and it was up to 3 m?1 for candled congelation ice in spring, and about 10 m?1 for superimposed ice (white ice) and snow. Gas bubbles were the main factor that reduced the transparency of ice. The radiation penetrating the ice heated the water body causing convective currents and horizontal heat transfer. This increased the temperature of the water body to about 3°C before the ice break-up. After the snow had melted, the euphotic depth (the depth of 1% surface irradiance) was estimated as 2.0 m, only two-thirds that in summer. 相似文献
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997.
Junji Otani Toshiyuki Nankumo Kyohei Arita Susumu Inamoto Mariko Ariyoshi Masahiro Shirakawa 《EMBO reports》2009,10(11):1235-1241
DNMT3 proteins are de novo DNA methyltransferases that are responsible for the establishment of DNA methylation patterns in mammalian genomes. Here, we have determined the crystal structures of the ATRX–DNMT3–DNMT3L (ADD) domain of DNMT3A in an unliganded form and in a complex with the amino‐terminal tail of histone H3. Combined with the results of biochemical analysis, the complex structure indicates that DNMT3A recognizes the unmethylated state of lysine 4 in histone H3. This finding indicates that the recruitment of DNMT3A onto chromatin, and thereby de novo DNA methylation, is mediated by recognition of the histone modification state by its ADD domain. Furthermore, our biochemical and nuclear magnetic resonance data show mutually exclusive binding of the ADD domain of DNMT3A and the chromodomain of heterochromatin protein 1α to the H3 tail. These results indicate that de novo DNA methylation by DNMT3A requires the alteration of chromatin structure. 相似文献
998.
Mutations in the CuZn superoxide dismutase (SOD1) and TAR DNA-binding protein 43 (TDP-43) genes are linked to familial amyotrophic lateral sclerosis, ALS1 and ALS10, respectively. In addition, TDP-43 is a major component protein of the ubiquitinated aggregates observed in sporadic ALS (SALS) patients. However, it remains unclear whether these ALS groups partly have a shared pathogenesis. In the present study, we demonstrate that mutant SOD1, but not wild-type SOD1, interacts with TDP-43 by co-immunoprecipitation assays using cultured cells and G93A mutant SOD1 transgenic mice. The region responsible for this interaction within SOD1 is the dimer interface, namely, the N- and C-terminal regions. Deletion mutants of TDP-43 with or without nuclear localization sequence interacted with mutant SOD1. Cell fractionation assays using cultured cells showed that mutant SOD1 was localized in the cytosolic fraction but not in the nuclear fraction. TDP-43 was detected both in the nuclear and cytosolic fractions, suggesting that mutant SOD1 interacts with TDP-43 in the cytoplasm. Mutant SOD1 overexpression led to an increased amount of mutant SOD1 and, to some extent, its interacting proteins including TDP-43 in the detergent-insoluble fraction. These results indicate that mutant SOD1 could affect the solubility/insolubility of its interacting proteins including TDP-43 through physical interactions. Our findings may contribute to the understanding of links among SALS, ALS1 and ALS10. 相似文献
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