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951.
Ornithine-containing lipids (OrnL) extracted from Flavobacterium meningosepticum have been reported to have various biological activities such as B-cell mitogenicity and macrophage activation to generate interleukin-1 and prostaglandin E2. We, using ovalbumin (OVA) as an antigen, evaluated the adjuvant activity of OrnL as an immunological adjuvant in BALB/c mice. OrnL showed the function of forming liposome-like vesicles retaining biological activities when prepared as either small unilamellar or dehydration-rehydration vesicles. Although OrnL was not shown to have enough entrapping efficacy for use as a vaccine adjuvant, phosphatidylglycerol (PG) and cholesterol (CHOL) added to stabilize the vesicle membrane increased the entrapping efficacy to the same extent as that of conventional liposomes. Furthermore, the stabilized OrnL vesicles tolerated centrifugation to remove non-entrapped antigens. Completely antigen-entrapped OrnL vesicles including PG and CHOL induced a significantly greater enhancement of IgG antibody production than did aluminum hydroxide gel in BALB/c mice from week 6. These results indicate that OrnL can be utilized as an immunological adjuvant for vaccines. 相似文献
952.
Precise measurements of the partial pressure of CO2 (PCO2) in oceanic and lagoonal surface waters from Palau Barrier Reef and Majuro Atoll were taken to ascertain the net effect of
these coral reef systems on air-sea CO2 exchange. PCO2 in the surface water in the lagoon of Palau Barrier Reef and Majuro Atoll was 48 and 14 μatm higher than in the surrounding
oceanic water, respectively. A total carbon dioxide vs. total alkalinity diagram indicates that calcification is mainly responsible
for CO2 evasion in these coral reef systems.
Accepted: 31 March 1997 相似文献
953.
Glutamate synthase (GOGAT) is a key enzyme in the assimilation of inorganic nitrogen in photosynthetic organisms. We found that, like higher plants, the facultative heterotrophic cyanobacterium Plectonema boryanum had ferredoxin (Fd)- and NADH-dependent GOGATs. The genes glsF, gltB, and gltD were cloned, and structural analyses and target mutageneses demonstrated that glsF encoded Fd-GOGAT and that gltB and gltD encoded the two subunits of NADH-GOGAT. All three mutants lacking one of the GOGAT genes were able to grow photosynthetically and heterotrophically. However, the Fd-GOGAT mutant exhibited a phenotype of marked nitrogen deficiency when grown under conditions of saturating illumination and CO2 supply. In these conditions the rate of the ammonia uptake from the culture medium was slower in the Fd-GOGAT mutant than in the wild type or in the NADH-GOGAT mutant, but no significant differences were found in the rate of the CO2 fixation-dependent O2 evolution among these strains. Our results suggest that, although both Fd- and NADH-GOGATs were operative in the cells growing in light, the contribution of Fd-GOGAT, which directly utilizes photoreducing power for the catalytic reaction, is essential for balancing photosynthetic nitrogen and carbon assimilation. 相似文献
954.
S. I. Faruki A. Miyanoshita K. Takahashi T. Misumi T. Imamura H. Naito M. Goto Y. Soma 《Journal of Applied Entomology》2005,129(1):12-16
Abstract: The efficacy of methyl iodide (MI) as a fumigant against all developmental stages of the maize weevil, Sitophilus zeamais Motsch. was investigated. Tests were conducted with concentrations of 1.5, 1.8, 2.1, 2.4, 2.7 and 3.0 mg/l, for a 6-h exposure period. Values of LC50 , LC95 and LC99 of MI for immatures and adult stages were determined. The present laboratory tests showed that MI was toxic to various life stages of S. zeamais at relatively short exposure periods. At the LC50 and LC95 levels, the most susceptible stage was the egg stage followed by larvae, pupae and adults (1-day mortality). The egg was found to be most susceptible to MI, requiring 0.81 and 2.16 mg/l for 50 and 99% mortality, respectively, while the adult was most tolerant, requiring 2.30 and 3.02 mg/l for 50 and 99% mortality, respectively, based on 1-day mortality count. Pupae were less susceptible to MI than egg and larvae, requiring 1.47 and 3.19 mg/l for 50 and 99% mortality, respectively. Based on the present toxicity tests, MI has the potential for use as a fumigant to control all developmental stages of the maize weevil, S. zeamais . 相似文献
955.
956.
Natural hybridization of Yezo and Sakhalin spruce in central Hokkaido,revealed by DNA markers with contrasting modes of inheritance 总被引:1,自引:0,他引:1 下载免费PDF全文
Mineaki Aizawa Hiroshi Yoshimaru Hitomi Ogawa Susumu Goto Mikio Kaji 《Plant Species Biology》2016,31(3):188-195
Yezo spruce (Picea jezoensis var. jezoensis) and Sakhalin spruce (Picea glehnii) occur across Hokkaido and co‐occur in some forest habitats. This leads to the potential for natural hybridization between these two species, which has been shown to occur at low frequencies. The purpose of this study was to identify these hybrids and their possible mating patterns, using various Pinaceae DNA markers with different modes of inheritance. The markers used were maternally inherited mitochondrial DNA (mtDNA), paternally inherited chloroplast DNA (cpDNA) and biparentally inherited nuclear microsatellites (nSSRs). Seven putative natural hybrids, four artificially‐crossed F1 hybrids, four parent plants from each species, and two artificially‐backcrossed hybrids of putative natural hybrids and their parents were analyzed using the diagnostic DNA markers developed in this study. We found Yezo spruce and Sakhalin spruce to be distinct (J and G types, respectively), and the modes of inheritance held true for the two species, as was previously reported to be the case in Pinaceae. Four of the seven putative natural hybrids harbored J‐type cpDNA, G‐type mtDNA and J/G‐type nSSRs, indicating that natural F1 hybrids are likely to arise from a G (female) × J (male) crossing. One natural hybrid harbored G‐type cpDNA, J‐type mtDNA and J/G‐type nSSRs, which implies that hybrids produced by J (female) × G (male) crossings occur at low frequencies. The two remaining hybrids harbored J‐type cpDNA and mtDNA with either J/G or J/J‐type nSSRs, suggesting that they may be F2 hybrids resulting from backcrossing between an F1 hybrid and a Yezo spruce. 相似文献
957.
Masanori Toyofuku Tomohiro Inaba Tatsunori Kiyokawa Nozomu Obana Yutaka Yawata 《Bioscience, biotechnology, and biochemistry》2016,80(1):7-12
Cells respond to the environment and alter gene expression. Recent studies have revealed the social aspects of bacterial life, such as biofilm formation. Biofilm formation is largely affected by the environment, and the mechanisms by which the gene expression of individual cells affects biofilm development have attracted interest. Environmental factors determine the cell’s decision to form or leave a biofilm. In addition, the biofilm structure largely depends on the environment, implying that biofilms are shaped to adapt to local conditions. Second messengers such as cAMP and c-di-GMP are key factors that link environmental factors with gene regulation. Cell-to-cell communication is also an important factor in shaping the biofilm. In this short review, we will introduce the basics of biofilm formation and further discuss environmental factors that shape biofilm formation. Finally, the state-of-the-art tools that allow us investigate biofilms under various conditions are discussed. 相似文献
958.
Hisako Nakagawa Takuya Shiozaki Eiji Kobatake Tomohiro Hosoya Tomohiro Moriya Fumihiko Sakai Hidenori Taru Tadaaki Miyazaki 《Aging cell》2016,15(2):227-236
Lactic‐acid bacteria are widely recognized beneficial host associated groups of the microbiota of humans and animals. Some lactic‐acid bacteria have the ability to extend the lifespan of the model animals. The mechanisms behind the probiotic effects of bacteria are not entirely understood. Recently, we reported the benefit effects of Lactobacillus gasseriSBT2055 (LG2055) on animal and human health, such as preventing influenza A virus, and augmentation of IgA production. Therefore, it was preconceived that LG2055 has the beneficial effects on longevity and/or aging. We examined the effects of LG2055 on lifespan and aging of Caenorhabditis elegans and analyzed the mechanism of prolongevity. Our results demonstrated that LG2055 has the beneficial effects on longevity and anti‐aging of C. elegans. Feeding with LG2055 upregulated the expression of the skn‐1 gene and the target genes of SKN‐1, encoding the antioxidant proteins enhancing antioxidant defense responses. We found that feeding with LG2055 directly activated SKN‐1 activity via p38 MAPK pathway signaling. The oxidative stress response is elicited by mitochondrial dysfunction in aging, and we examined the influence of LG2055 feeding on the membrane potential of mitochondria. Here, the amounts of mitochondria were significantly increased by LG2055 feeding in comparison with the control. Our result suggests that feeding with LG2055 is effective to the extend lifespan in C. elegans by a strengthening of the resistance to oxidative stress and by stimulating the innate immune response signaling including p38MAPK signaling pathway and others. 相似文献
959.
With the rapid fragmentation of tropical forests harboring valuable tree species, conservation of natural genetic resources is an important issue. In Myanmar, teak plantations have been established by Myanmar government since the 1700 s using local Myanmar teak. Commercial plantations have recently been established by the private sector using both exotic and Myanmar teak without consideration of their genetic make-up. If the genetic composition of commercial teak plantations is severely different from that of Myanmar teak, introgression of non-indigenous genes could damage the remaining natural populations. We investigated genetic compositions of commercial plantations using both exotic and Myanmar teak seeds with 10 nuclear simple sequence repeat and three chloroplast single nucleotide polymorphism markers. We then compared the genetic compositions of these populations with those of neighboring native teak forests. The genetic diversity and composition of one exotic plantation using Costa Rican seeds was similar to those of native populations. However, the diversity of the other three exotic plantations was low and their composition was markedly different from those of native populations. Our results suggest that exotic gene flow would cause serious genetic disturbance. Commercial plantations using Myanmar seeds were characterized by relatively high genetic diversity and by many genetic components. These results suggest that these plantations may be established using various seed sources in Myanmar. Given that native teak in Myanmar is geographically structured, native gene pools will be homogenized by gene flow from these commercial plantations. Seed transfer guidelines based on genetic information should be considered in future. 相似文献
960.
Shugo Fujibayashi Junpei Sasajima Takuma Goto Hiroki Tanaka Hidemasa Kawabata Tsuneshi Fujii Kazumasa Nakamura Atsushi Chiba Nobuyuki Yanagawa Kentaro Moriichi Mikihiro Fujiya Yutaka Kohgo 《Biochemistry and Biophysics Reports》2016
The pathogenesis of autoimmune pancreatitis is unknown. In the present study we used high-throughput sequencing with next generation sequencing to identify the candidate genes associated with AIP. A total of 27 type 1 AIP patients and 30 healthy blood donors were recruited, and DNA samples were isolated from their mononuclear cells. A high-throughput sequencer with an original custom panel of 1031 genes was used to detect the genetic variants in each sample. Polymorphisms of CACNA1S (c.4642C>T), rs41554316, rs2231119, rs1042131, rs2838171, P2RX3 (c.195delG), rs75639061, SMAD7 (c.624delC) and TOP1 (c.2007delG), were identified as candidate genetic variants in patients with type 1 AIP. P2RX3 and TOP1 were significantly associated with AIP, even after adjusting bay means of Bonferroni's correction. In addition, we also identified eight candidate genetic variants that were associated with the relapse of type 1 AIP, namely: rs1143146, rs1050716, HLA-C (c.759_763delCCCCCinsTCCCG), rs1050451, rs4154112, rs1049069, CACNA1C (c.5996delC) and CXCR3 (c.630_631delGC). Finally polymorphisms of rs1050716 and rs111493987 were identified as candidate genetic variants associated with extra-pancreatic lesions in patients with type 1 AIP. These candidates might be used as markers of AIP susceptibility and could contribute to the pathogenesis of type 1 AIP. 相似文献