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1.
Motoshige Kawata Satoshi Harada Baltazar Antonio Kiyoharu Oono 《Plant Cell, Tissue and Organ Culture》1992,28(1):1-10
Protoplasts were isolated from callus derived from a single homozygous seed of Oryza sativa L. var. Norin 8. Thirty protoclones were randomly selected and these showed variation in regeneration frequency ranging from 0–87% with an average of 52%. The potential for regeneration of each protoclone as reflected in the regeneration frequency was analyzed five times over a period of 250 days and showed that the protoclones can be classified into three types, namely: protoclones with high regeneration frequency; protoclones with low regeneration frequency, both of which maintained their respective levels of regeneration potential; and protoclones with gradually decreasing regeneration frequency. Secondary protoclones established from protoplasts isolated from some of these protoclones and regenerated 2–3 times for a period of 120 days also showed further reduction in regeneration frequency. The polypeptide composition analyzed by two dimensional gel electrophoresis suggests the presence of specific polypeptides related to regeneration potential. Analysis of ploidy level based on plant morphology and pollen size suggests the predominance of tetraploids among the regenerated plants. 相似文献
2.
Atomic force microscopic images of single skeletal myofibrils showed periodical broad filamentous bands interspaced with narrow rigid bands corresponding to the sarcomere structures of skeletal muscle (Yoshikawa, Y., Yasuike, T., Yagi, A., and Yamada, T. 1999. Biochem. Biophys. Res. Comm., 256: 13-19). In order to identify the narrow rigid bands, comparative studies were made for intact single myofibrils and those treated with calcium-activated neutral protease by use of atomic force microscopy. It was found that (a) the periodical narrow rigid bands present in intact myofibrils were completely absent in myofibrils treated with calcium-activated neutral protease, and that (b) myofibrils treated with calcium-activated neutral protease were very fragile compared with intact myofibrils. As calcium-activated neutral protease selectively removes Z-bands of myofibrils (Reddy, M. K., Etlinger, J. D., Rabinowitz, M., Fischman, D. A., and Zak, R. 1975. J. Biol. Chem., 250: 4278-4284), these results clearly indicate that (a) the narrow rigid bands are the Z-bands, and that (b) the Z-bands are the essential disc supporting the sarcomere structure of skeletal muscle. 相似文献
3.
Molecular characterization and gene expression of a CXC chemokine gene from Japanese flounder Paralichthys olivaceus 总被引:1,自引:0,他引:1
Chemokines are small, secreted cytokine peptides that have the ability to recruit a wide range of immune cells to sites of infection and disease. A novel CXC chemokine was obtained from Japanese flounder Paralichthys olivaceus. This chemokine cDNA contains an open reading frame of 333 nucleotides encoding 111 amino acid residues containing four conserved cysteine residues. The gene is composed of four exons and three introns as are those of mammalian and fish CXC chemokines. Results of homology and phylogenetic analysis revealed that the Japanese flounder CXC chemokine is closest to CXCL13 subgroup. The gene was expressed in immune-related organs, including head kidney, trunk kidney, spleen and peripheral blood leukocytes (PBLs). Japanese flounder CXC chemokine gene expression was observed at 3 and 6h after induction by LPS, but not at 3 and 6h after induction by poly I:C. These results suggest that the Japanese flounder CXC chemokine is probably associated with inflammatory as well as homeostatic functions. 相似文献
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5.
2-Keto-3-deoxygluconate kinase (KDGK) catalyzes the phosphorylation of 2-keto-3-deoxygluconate (KDG) to 2-keto-3-deoxy-6-phosphogluconate (KDGP). The genome sequence of Thermus thermophilus HB8 contains an open reading frame that has a 30% identity to Escherichia coli KDGK. The KDGK activity of T.thermophilus protein (TtKDGK) has been confirmed, and its crystal structure has been determined by the molecular replacement method and refined with two crystal forms to 2.3 angstroms and 3.2 angstroms, respectively. The enzyme is a hexamer organized as a trimer of dimers. Each subunit is composed of two domains, a larger alpha/beta domain and a smaller beta-sheet domain, similar to that of ribokinase and adenosine kinase, members of the PfkB family of carbohydrate kinases. Furthermore, the TtKDGK structure with its KDG and ATP analogue was determined and refined at 2.1 angstroms. The bound KDG was observed predominantly as an open chain structure. The positioning of ligands and the conservation of important catalytic residues suggest that the reaction mechanism is likely to be similar to that of other members of the PfkB family, including ribokinase. In particular, the Asp251 is postulated to have a role in transferring the gamma-phosphate of ATP to the 5'-hydroxyl group of KDG. 相似文献
6.
M. Yasuike S. Jantzen G. A. Cooper E. Leder W. S. Davidson B. F. Koop 《Journal of fish biology》2010,76(2):395-400
The phylogenetic relationships among the three subfamilies (Salmoninae, Coregoninae and Thymallinae) in the Salmonidae have not been addressed extensively at the molecular level. In this study, the whole mitochondrial genomes of two Thymallinae species, Thymallus arcticus and Thymallus thymallus were sequenced, and the published mitochondrial genome sequences of other salmonids were used for Bayesian and maximum‐likelihood phylogenetic analyses. These results support an ancestral Coregoninae, branching within the Salmonidae, with Thymallinae as the sister group to Salmoninae. 相似文献
7.
Antiangiogenic and antitumor activities of IL-27 总被引:10,自引:0,他引:10
Shimizu M Shimamura M Owaki T Asakawa M Fujita K Kudo M Iwakura Y Takeda Y Luster AD Mizuguchi J Yoshimoto T 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(12):7317-7324
IL-27 is a novel IL-6/IL-12 family cytokine playing an important role in the early regulation of Th1 responses. We have recently demonstrated that IL-27 has potent antitumor activity, which is mainly mediated through CD8(+) T cells, against highly immunogenic murine colon carcinoma. In this study, we further evaluated the antitumor and antiangiogenic activities of IL-27, using poorly immunogenic murine melanoma B16F10 tumors, which were engineered to overexpress single-chain IL-27 (B16F10 + IL-27). B16F10 + IL-27 cells exerted antitumor activity against not only s.c. tumor but also experimental pulmonary metastasis. Similar antitumor and antimetastatic activities of IL-27 were also observed in IFN-gamma knockout mice. In NOD-SCID mice, these activities were decreased, but were still fairly well-retained, suggesting that different mechanisms other than the immune response are also involved in the exertion of these activities. Immunohistochemical analyses with Abs against vascular endothelial growth factor and CD31 revealed that B16F10 + IL-27 cells markedly suppressed tumor-induced neovascularization in lung metastases. Moreover, B16F10 + IL-27 cells clearly inhibited angiogenesis by dorsal air sac method, and IL-27 exhibited dose-dependent inhibition of angiogenesis on chick embryo chorioallantoic membrane. IL-27 was revealed to directly act on HUVECs and induce production of the antiangiogenic chemokines, IFN-gamma-inducible protein (IP-10) and monokine induced by IFN-gamma. Finally, augmented mRNA expression of IP-10 and monokine induced by IFN-gamma was detected at the s.c. B16F10 + IL-27 tumor site, and antitumor activity of IL-27 was partially inhibited by the administration of anti-IP-10. These results suggest that IL-27 possesses potent antiangiogenic activity, which plays an important role in its antitumor and antimetastatic activities. 相似文献
8.
Fagutao FF Yasuike M Caipang CM Kondo H Hirono I Takahashi Y Aoki T 《Marine biotechnology (New York, N.Y.)》2008,10(6):731-740
Shrimps are believed to lack an adaptive immune system and therefore rely heavily on their innate immune mechanisms to ward
off pathogens. Moreover, their innate defense reactions are triggered by bacterial and fungal cell wall components such as
lipopolysaccharides, peptidoglycan and β-glucans. In this study, we used microarray to examine the gene expression profile
of kuruma shrimp, Marsupenaeus japonicus, after stimulation with peptidoglycan. Subsequent results show that the number of upregulated genes and percentage of differential
expression (21%) was highest at day 1 poststimulation. Differentially expressed genes in day 7 and day 14, on the other hand,
were 3.25% and 11.21%, respectively. Sixty-one (61) genes of unknown function were found to have responded outright to peptidoglycan
(PG) stimulation. Administration of PG also caused increases in the expressions of crustin, lysozyme, and a few antibacterial
peptides, all of which are known to be involved in crustacean immune response. Taken together, our results suggest that innate
response in shrimp is triggered instantaneously upon exposure to a bacterial component.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Yazawa R Yasuike M Leong J von Schalburg KR Cooper GA Beetz-Sargent M Robb A Davidson WS Jones SR Koop BF 《Marine biotechnology (New York, N.Y.)》2008,10(6):741-749
Nuclear deoxyribonucleic acid sequences from approximately 15,000 salmon louse expressed sequence tags (ESTs), the complete
mitochondrial genome (16,148bp) of salmon louse, and 16S ribosomal ribonucleic acid (rRNA) and cytochrome oxidase subunit
I (COI) genes from 68 salmon lice collected from Japan, Alaska, and western Canada support a Pacific lineage of Lepeophtheirus salmonis that is distinct from that occurring in the Atlantic Ocean. On average, nuclear genes are 3.2% different, the complete mitochondrial
genome is 7.1% different, and 16S rRNA and COI genes are 4.2% and 6.1% different, respectively. Reduced genetic diversity within the Pacific form of L. salmonis is consistent with an introduction into the Pacific from the Atlantic Ocean. The level of divergence is consistent with the
hypothesis that the Pacific form of L. salmonis coevolved with Pacific salmon (Onchorhynchus spp.) and the Atlantic form coevolved with Atlantic salmonids (Salmo spp.) independently for the last 2.5–11 million years. The level of genetic divergence coincides with the opportunity for
migration of fish between the Atlantic and Pacific Ocean basins via the Arctic Ocean with the opening of the Bering Strait,
approximately 5 million years ago. The genetic differences may help explain apparent differences in pathogenicity and environmental
sensitivity documented for the Atlantic and Pacific forms of L. salmonis.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
Mizuki Yamada Tsutomu Takahashi Mai Hasegawa Mio Matsumura Kanna Ono Ryota Fujimoto Yuki Kitamura Yuki Murata Naoki Kakusawa Motohiro Tanaka Tohru Obata Yasuyuki Fujiwara Shuji Yasuike 《Bioorganic & medicinal chemistry letters》2018,28(2):152-154
Trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a–f) were synthesized by the Cu-catalyzed azide-alkyne cycloaddition of various ethynylstibanes (1) with benzylazide (2) in the presence of CuBr (5 mol%) under aerobic conditions. The reaction of 5-stibanotriazoles with HCl afforded C5-unsubstituted 1,2,3-triazoles (4a–f). The antitumor activity of trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a–f) and their 5-unsubstituted 1,2,3-triazoles (4a–f) were evaluated in several tumor cell lines. All 5-stibanotriazoles (3a–f) exerted an excellent antitumor activity. On the contrary, 5-unsubstituted 1,2,3-triazoles (4a–f) without a diphenylantimony group in the molecule exhibited very low antitumor activity compared with 5-stibanotriazoles (3a–f). In compounds of both the series, the substituted 4-butyl group appeared to decrease antitumor activity. However, results suggested that organometal (antimony) in the molecule was required for greater antitumor activity. In addition, all 5-stibanotriazoles (3a–f), but not all 5-unsubstituted 1,2,3-triazoles (4a–f), exhibited cytotoxicity in normal vascular endothelial cells derived from bovine aorta. Among the compounds (3b–e) that exhibited excellent antitumor activity, those with 4-methylphenyl (3b) and 1-cyclohexenyl (3e) showed relatively low cytotoxicity to vascular endothelial cells. Together, these results suggest that trisubstituted 5-organostibano-1H-1,2,3-triazoles, including compounds 3b and 3e, may serve as potential anticancer therapeutic drugs in the future. 相似文献