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101.
A simple and efficient procedure for labeling neurons is a prerequisite for investigating the development of neural networks in zebrafish. To label neurons we used Kaede, a fluorescent protein with a photoconversion property allowing conversion from green to red fluorescence following irradiation with UV or violet light. We established a zebrafish stable transgenic line, Tg(HuC:Kaede), expressing Kaede in neurons under the control of the HuC promoter. This transgenic line was used to label a small number of neurons in the trigeminal ganglion. Also, using embryos injected with the transgene, we labeled peripheral axon arbors of a Rohon-Beard neuron at 4 days postfertilization and observed the dendrite development of a tectal neuron for 3 days. These data indicate that Kaede is a useful tool to selectively label neural networks in zebrafish. 相似文献
102.
Yasuo Imanishi Masaaki Inaba Hitoshi Seki Hidenori Koyama Yoshiki Nishizawa Hirotoshi Morii Shuzo Otani 《The Journal of steroid biochemistry and molecular biology》1999,70(4-6)
1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) is known to be involved in regulating the proliferation of parathyroid cells and PTH synthesis through reactions involving its nuclear receptor. We evaluated the effects of 1,25-(OH)2D3 and its hexafluorinated analog, 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 (26,27-F6-1,25-(OH)2D3), on parathyroid cells. The 1,25-(OH)2D3 and 26,27-F6-1,25-(OH)2D3 each inhibited [3H]thymidine incorporation and ornithine decarboxylase (ODC) activity, which is important in cell proliferation, in primary cultured bovine parathyroid cells. The inhibitory effect of 26,27-F6-1,25-(OH)2D3 on PTH secretion from parathyroid cells was significantly more potent than that of 1,25-(OH)2D 3 between 10−11 M and 10−8 M. Study of 26,27-F6-1,25-(OH)2D3 metabolism in parathyroid cells in vitro elucidated its slower degradation than that of 1,25-(OH)2D3. After 48 h of incubation with [1β-3H]26,27-F6-1,25-(OH)2D3, two HPLC peaks, one for [1β-3H]26,27-F6-1,25-(OH)2D3, and a second larger peak for [1β-3H]26,27-F6-1,23(S),25-(OH)3D3, were detected. No metabolites were detected after the same period of incubation with 1,25-(OH)2[26,27-3H]D3. We observed that 26,27-F6-1,23(S),25-(OH)3D3 was as potent as 1,25-(OH)2D3 in inhibiting the proliferation of parathyroid cells.Data suggest that the greater biological activity of 26,27-F6-1,25-(OH)2D3 is explained by its slower metabolisms and by the retention of the biological potency of 26,27-F6-1,25-(OH)2D3 even after 23(S)-hydroxylation. 相似文献
103.
Jia-Xing Yue Jinpeng Li Dan Wang Hitoshi Araki Dacheng Tian Sihai Yang 《BMC plant biology》2010,10(1):242
Background
Rates of molecular evolution vary widely among species. While significant deviations from molecular clock have been found in many taxa, effects of life histories on molecular evolution are not fully understood. In plants, annual/perennial life history traits have long been suspected to influence the evolutionary rates at the molecular level. To date, however, the number of genes investigated on this subject is limited and the conclusions are mixed. To evaluate the possible heterogeneity in evolutionary rates between annual and perennial plants at the genomic level, we investigated 85 nuclear housekeeping genes, 10 non-housekeeping families, and 34 chloroplast genes using the genomic data from model plants including Arabidopsis thaliana and Medicago truncatula for annuals and grape (Vitis vinifera) and popular (Populus trichocarpa) for perennials. 相似文献104.
Miyake K Tsukui T Shinji Y Shinoki K Hiratsuka T Nishigaki H Futagami S Wada K Gudis K Iwakiri K Yamada N Sakamoto C 《Helicobacter》2004,9(2):130-137
Background. The role of teprenone in Helicobacter pylori‐associated gastritis has yet to be determined. To investigate the effect of teprenone on inflammatory cell infiltration, and on H. pylori colonization of the gastric mucosa in H. pylori‐infected patients, we first compared the effect of teprenone with that of both histamine H2 receptor antagonists (H2‐RA) and sucralfate on the histological scores of H. pylori gastritis. We then examined its in vitro effect on H. pylori‐induced interleukin (IL)‐8 production in MKN28 gastric epithelial cells. Materials and Methods. A total of 68 patients were divided into three groups, each group undergoing a 3‐month treatment with either teprenone (150 mg/day), H2‐RA (nizatidine, 300 mg/day), or sucralfate (3 g/day). All subjects underwent endoscopic examination of the stomach before and after treatment. IL‐8 production in MKN28 gastric epithelial cells was measured by enzyme‐linked immunosorbent assay (ELISA). Results. Following treatment, the teprenone group showed a significant decrease in both neutrophil infiltration and H. pylori density of the corpus (before vs. after: 2.49 ± 0.22 vs. 2.15 ± 0.23, p = .009; 2.36 ± 0.25 vs. 2.00 ± 0.24, p = .035, respectively), with no significant differences seen in either the sucralfate or H2‐RA groups. Teprenone inhibited H. pylori‐enhanced IL‐8 production in MKN28 gastric epithelial cells in vitro, in a dose‐dependent manner. Conclusions. Teprenone may modify corpus H. pylori‐associated gastritis through its effect on neutrophil infiltration and H. pylori density, in part by its inhibition of IL‐8 production in the gastric mucosa. 相似文献
105.
Sebastian K. Klosek Shingo Hara Hitoshi Hasegawa 《Biochemical and biophysical research communications》2009,379(4):1097-15874
We previously demonstrated that CD151 forms a functional complex with c-Met and integrin α3/α6 in human salivary gland cancer cells. In the current study, we investigated the involvement of CD151, c-Met, and integrin α3/α6 in the cellular morphogenesis of human breast cancer cells. Knockdown of CD151, integrin α3, or integrin α6 expression abolished branching morphogenesis. Decreased c-Met expression in these cells led to the formation of rudimentary networks and prevented their conversion. Furthermore, hepatocyte growth factor (HGF) promoted cellular morphogenesis by accelerating network reorganization. Immunoprecipitation revealed a specific association between CD151 and c-Met. The involvement of CD151 and integrin α3/α6 in HGF-dependent signaling was confirmed by the decreased Akt phosphorylation in cells lacking CD151, integrin α3, or integrin α6. Hence, the regulation of CD151 expression might contribute to changes in HGF/c-Met signaling and thereby modulate the phenotypic characteristics of cancer cells. 相似文献
106.
Defining Developmental Potency and Cell Lineage Trajectories by Expression Profiling of Differentiating Mouse Embryonic Stem Cells 总被引:1,自引:0,他引:1 下载免费PDF全文
107.
Jun‐ichi Itoh Ken‐ichiro Hibara Mikiko Kojima Hitoshi Sakakibara Yasuo Nagato 《The Plant journal : for cell and molecular biology》2012,72(6):869-881
Phyllotaxy is defined as the spatial arrangement of leaves on the stem. The mechanism responsible for this extremely regular pattern is one of the most fascinating enigmas in plant biology. In this study, we identified a gene regulating the phyllotactic pattern in rice. Loss‐of‐function mutants of the DECUSSATE (DEC) gene displayed a phyllotactic conversion from normal distichous pattern to decussate. The dec mutants had an enlarged shoot apical meristem with enhanced cell division activity. In contrast to the shoot apical meristem, the size of the root apical meristem in the dec mutants was reduced, and cell division activity was suppressed. These phenotypes indicate that DEC has opposite functions in the shoot apical meristem and root apical meristem. Map‐based cloning revealed that DEC encodes a plant‐specific protein containing a glutamine‐rich region and a conserved motif. Although its molecular function is unclear, the conserved domain is shared with fungi and animals. Expression analysis showed that several type A response regulator genes that act in the cytokinin signaling pathway were down‐regulated in the dec mutant. In addition, dec seedlings showed a reduced responsiveness to exogenous cytokinin. Our results suggest that DEC controls the phyllotactic pattern by affecting cytokinin signaling in rice. 相似文献
108.
Eggs of Oryzius latipes in the blastula stage were exposed to M/100 artificial sea water which contained cadmium at the concentrations of 0.1, 1.0, 10.0, 20.0 or 50.0 mg 1−1 . The 96 h TL50 , value for cadmium was estimated to be 20 5 mg 1−1 . When the eggs were incubated for 24 h in the M/100 sea water with 10.0 mg Cd 1−1 and then rinsed in glycine buffer solution (pH; 2.0), the cadmium content of the egg decreased markedly. Cadmium levels were determined in parts of the embryonic body, the chorion and the yolk sac. The most cadmium was detected in the chorion (94.6%). Prolonged cadmium exposure revealed that most of the cadmium was absorbed by the chorion and little was detected in the embryonic body and the yolk sac. 相似文献
109.
Ichiro Iuchi Chang-Rak Ha Hitoshi Sugiyama Kohji Nomura 《Development, growth & differentiation》1996,38(3):299-306
We estimated changes of chorion hardness of rainbow trout (Oncorhynchus mykiss) egg by the use of three parameters, namely increase of resistance of an egg to rupture by extraneously applied pressure, decrease of solubility of chorion proteins in 8 mol/L urea and a change in the content of γ-glutamyl-ε-lysine crosslink. Unfertilized egg chorions became hardened after egg activation. During chorion hardening, 49, 56 and 65 kDa protein components of the chorion gradually disappeared, high molecular weight intermediates (113,160–170 and higher than 250 kDa) were newly formed and, finally, all components became undetectable by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The content of γ-glutamyl-ε-lysine (γ-Glu-ε-Lys) crosslink in the chorion increased after hardening. Chorion hardening was inhibited by the incorporation of monodansyl-cadaverine, a competitive inhibitor for transglutaminase (TGase), into the chorions. TGase activity was detected in unfertilized eggs and localized in the chorion fraction rather than in the ooplasmic fraction. The findings suggest that chorion hardening depends upon polymerization of the chorion components by TGase-dependent γ-Glu-ε-Lys crosslink formation. 相似文献
110.
cDNA Cloning of Indole-3-Acetic Acid-Regulated Genes: Aux22 and SAUR from Mung Bean (Vigna radiata) Hypocotyl Tissue 总被引:3,自引:0,他引:3
Five cDNAs of auxin-regulated genes were isolated from mungbean (Vigna radiata) hypocotyl sections by differential hybridizationscreening. They were related to the soybean genes, Aux22 [Ainleyet al. (1988) J. Biol. Chem. 263: 10658] and SAUR [McClure etal. (1989) Plant Cell 1: 229]. Regulation of expression of thesegenes, examined by Northern blot analysis, appeared similarto that reported in soybean hypocotyls. (Received August 10, 1991; Accepted October 14, 1991) 相似文献