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11.
Tada Mikiro; Shiroishi Masahide; Hasegawa Kiyozo; Suzuki Tetsuya; Iwai Kazuo 《Plant & cell physiology》1982,23(4):607-614
The effect of light on the production of ergosterol and phytoeneand on the composition of carotenoids in Rhodotorula minutawas studied to determine which part of the pathway of carotenoidsynthesis regulated by light. The ergosterol content in the cells was in the range of 3.43.6mg/g dry cells regardless of the presence or absence of illuminationand the light intensity. The phytoene production in the cellswas markedly stimulated by light and was dependent on the lightintensity according to the amount of carotenoid pigments produced.In addition, the ratio of phytoene to carotenoid was in therange of 0.360.44, regardless of the presence or absenceof illumination and the light intensity. The fact that the ratio of carotenoid fractionated on the basisof the functional group involved in each carotenoid to the totalamount of carotenoid was almost constant regardless of the lightintensity suggested that the composition of the carotenoidssynthesized in the cells is not affected by light. It was deduced from these results that light induced the productionof enzyme(s) required for phytoene biosynthesis in Rhodotorulaminuta. (Received November 7, 1981; Accepted March 19, 1982) 相似文献
12.
Takashi Iwamoto Masahide Takahashi Masaharu Ohbayashi Izumi Nakashima 《Experimental cell research》1992,200(2)
We recently reported the establishment of transgenic mouse lines carrying the mouse metallothionein/ret fusion gene in which severe melanosis and melanocytic tumors developed. In the present study, we demonstrate that a significant number of pigmented hairs developed in Wv/Wv mice crossed to one of the transgenic mouse lines. The pigmented hair of Wv/Wv mice carrying the ret oncogene did not lose color during aging and reappeared after shaving, indicating that the melanocytes in the hair follicle function. The melanocytic tumors also developed in these mice, although the incidence was lower than that in the wild transgenic mice. Furthermore, the neural tube culture of mouse embryos indicated that neural crest cells of the transgenic mice gave rise to a cell population that autonomously produced melanin even in the absence of melanocyte stimulating hormone. These results strongly suggested that the introduced ret oncogene could compensate for the defect of c-kit in Wv mice during both embryogenesis and postnatal life and induce a high level of melanin synthesis in the process of melanocyte development. 相似文献
13.
Absorption, linear dichroism and circular dichroism spectra of Rhodopseudomonas capsulata (wild-type-St. Louis strain, mutant Y5 and mutant Ala+) are particularly sensitive to the nature of the light-harvesting bacteriochlorophyll-carotenoid-protein complexes. Evidence for exciton-type interactions is seen near 855 nm in the membranes from the wild-type and from mutant Y5, as well as in an isolated B-800 + 850 light-harvesting complex from mutant Y5. The strong circular dichroism that reflects these interactions is attenuated more than 10-fold in membranes from the Ala+ mutant, which lacks both B-800 + 850 and colored carotenoids and contains only the B-875 light-harvesting complex. These results lead to the conclusion that these two light-harvesting complexes have significantly different chromophore arrangements or local environments. 相似文献
14.
Eizo Sada Shigeo Katoh Masami Shiozawa Tsunehiko Fukui 《Biotechnology and bioengineering》1981,23(11):2561-2567
The performance of fluidized-bed reactors utilizing a magnetic field was determined by the use of magnetite-containing beads of immobilized unease. The reactors showed similar or higher conversions in comparison with fixed-bed reactors, although some aggregation of the beads in the magnetic field was observed. No effusion of the beads occurred up to a flow rate of 24 cm/min. 相似文献
15.
Keishi Abe Yoichi Otsuka Minoru Yasujima Satoru Ciba Masahide Seino Nobuo Irokawa Kaoru Yoshinaga Fumio Hirata Shiro Ohki Nobuhiko Nakazawa Toshio Hanyu 《Prostaglandins & other lipid mediators》1976,12(5):843-848
The excretion rates of main urinary metabolite of PG F2α were measured radioimmunologically in 4 healthy persons and in 13 essential hypertensives. The resting values were 9.3±0.73 in the former and 10.4±2.17 ng/min in the latter. There was no significant differences between them. The excretion of the metabolite decresed prominently after the administration of furosemide. The percent decrease was 57% in healthy persons and 70% in essential hypertension. The percent result supports that furosemide inhibit the catabolism of PG F2α. 相似文献
16.
Masahide Nonaka 《Phytochemistry》1985,25(1):73-75
Eight saponins were isolated from alfalfa roots (Medicago sativa). The sensitivity of Trichoderma viride to the saponin varied with the individual saponin isolate. Seven isolates appeared to contain the aglycone, medicagenic acid, and while the other did not, it inhibited the growth of the fungus at higher concentrations than the other isolates. One pair and a triplet of saponins with divergent Rfs evoked near identical biological responses suggesting structural similarity toxic to T. viride. 相似文献
17.
18.
Life-history theory predicts the occurrence of variation in the life-history traits of fish populations under different environmental conditions; however, most studies have focused on such variation between geographically separated populations. We compared breeding characteristics and life-history traits of the Japanese fluvial sculpin (Cottus pollux), a bottom-dwelling nest-holding fish, between two adjacent sites sub-divided by a weir along a stream course in central Japan. Males in the area with a lower abundance of nest sites reached sexual maturity at an earlier age and had a shorter life span than males in the area with sufficient nest abundance. Size-dependent male reproduction was found only in areas with a shortage of nest sites, supporting the assumption of competitive exclusion among males for nests. Females matured at the same age in both sites with no differences in age-specific growth rates and mortality. Our results provide evidence for life-history variation in age and size at maturity and age-specific mortality schedule of males in nest-holding fishes in a single stream population via different sexual selection regimes related to differences in nest abundance between sites. 相似文献
19.
Satomi Nadanaka Shaobo Zhou Shoji Kagiyama Naoko Shoji Kazuyuki Sugahara Kazushi Sugihara Masahide Asano Hiroshi Kitagawa 《The Journal of biological chemistry》2013,288(13):9321-9333
Mutant alleles of EXT1 or EXT2, two members of the EXT gene family, are causative agents in hereditary multiple exostoses, and their gene products function together as a polymerase in the biosynthesis of heparan sulfate. EXTL2, one of three EXT-like genes in the human genome that are homologous to EXT1 and EXT2, encodes a transferase that adds not only GlcNAc but also N-acetylgalactosamine to the glycosaminoglycan (GAG)-protein linkage region via an α1,4-linkage. However, both the role of EXTL2 in the biosynthesis of GAGs and the biological significance of EXTL2 remain unclear. Here we show that EXTL2 transfers a GlcNAc residue to the tetrasaccharide linkage region that is phosphorylated by a xylose kinase 1 (FAM20B) and thereby terminates chain elongation. We isolated an oligosaccharide from the mouse liver, which was not detected in EXTL2 knock-out mice. Based on structural analysis by a combination of glycosidase digestion and 500-MHz 1H NMR spectroscopy, the oligosaccharide was found to be GlcNAcα1-4GlcUAβ1–3Galβ1–3Galβ1–4Xyl(2-O-phosphate), which was considered to be a biosynthetic intermediate of an immature GAG chain. Indeed, EXTL2 specifically transferred a GlcNAc residue to a phosphorylated linkage tetrasaccharide, GlcUAβ1–3Galβ1–3Galβ1–4Xyl(2-O-phosphate). Remarkably, the phosphorylated linkage pentasaccharide generated by EXTL2 was not used as an acceptor for heparan sulfate or chondroitin sulfate polymerases. Moreover, production of GAGs was significantly higher in EXTL2 knock-out mice than in wild-type mice. These results indicate that EXTL2 functions to suppress GAG biosynthesis that is enhanced by a xylose kinase and that the EXTL2-dependent mechanism that regulates GAG biosynthesis might be a “quality control system” for proteoglycans. 相似文献
20.
Koji Ueda Keitaro Tawaraya Hideki Murayama Satoru Sato Takashi Nishizawa Tomonobu Toyomasu Tetsuya Murayama Shinpei Shiozawa Hironori Yasuda 《Applied Entomology and Zoology》2013,48(1):79-85
We investigated the effects of symbiotic association between a plant and an arbuscular mycorrhizal fungus (AMF) on the abundance of aboveground foliar-feeding insects that differed in feeding mode and their predator. We examined effects on insect abundance as the result of AMF-related changes in the quality and quantity of plants in the field. The numbers of three insects with different foliar-feeding mode (phloem feeder, chewer, and cell-content feeder) and their generalist predator Orius sauteri Poppius on soybean Glycine max (L.) Merrill with and without the AMF Gigaspora margarita Becker & Hall were compared over time. Symbiotic association between the AMF and the soybean increased shoot biomass, the concentration of phosphorus in the soybean, and the abundance of the phloem feeder Aulacorthum solani Kaltenbach, but did not affect the abundance of generalist chewers. In addition, the effects of the symbiotic association on the abundance of cell-content feeding Thrips spp. and the generalist predator O. sauteri differed between sample dates. These results indicated that the effects of the symbiotic association on the number of foliar-feeding insects depended on feeding mode and the number of predators. 相似文献