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41.
The zebrafish no tail gene (ntl) is indispensable for the formation of the notochord and the tail structure. Here we showed that de novo DNA methylation occurred at the CpG island of ntl. The methylation started at the segmentation stage and continued after the larval stage. However, it occurred predominantly between 14 and 48 h postfertilization, which overlaps the period in which ntl expression disappears in the notochord and the tailbud. This inverse correlation, together with the methylation-associated formation of an inaccessible chromatin structure at the ntl CpG island region, suggested the involvement of the de novo methylation in ntl repression. Since no changes in methylation patterns were observed at the CpG islands of four other zebrafish genes, there must be a mechanism in zebrafish for specific methylation of the ntl CpG island. 相似文献
42.
Identification of volicitin-related compounds from the regurgitant of lepidopteran caterpillars 总被引:3,自引:0,他引:3
Mori N Yoshinaga N Sawada Y Fukui M Shimoda M Fujisaki K Nishida R Kuwahara Y 《Bioscience, biotechnology, and biochemistry》2003,67(5):1168-1171
Volicitin-related compounds were found in the oral secretion of the three noctuid species, Helicoverpa armigera, Mythimna separata and Spodoptera litura, and one sphingid species, Agrius convolvuli. Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine], N-(17-hydroxylinoleoyl)-glutamine, N-linolenoylglutamine and N-linoleoylglutamine were identified in the secretion from the noctuid larvae. In secretions from the sphingid larvae, N-linolenoylglutamine and N-linoleoylglutamine were the main components. Furthermore, there were significant differences in the amounts of the N-acylamino acid conjugates in the secretions from the three noctuid species. These results suggest that the proportion of volicitin-related compounds in the regurgitant was species-specific. 相似文献
43.
Ishikawa H Shimoda M Yonekura A Mishima K Matsumoto K Osajima Y 《Bioscience, biotechnology, and biochemistry》2000,64(6):1295-1297
The conformational changes in alpha-helical poly-L-glutamic acid caused by microbubbling supercritical CO2 were investigated with circular dichroism spectra. After microbubbling using a micropore filter at 35 and 30 MPa for 30 min, alpha-helix content decreased to 37%, while without the filter it was 68%. The alpha-helix structure was significantly decomposed by a high density of CO2. No important changes were observed in heating, autoclaving, or pH-lowering. 相似文献
44.
To evidence the notion that gangliosides involve neuronal cell interactions in the brain, we surveyed the presence of ganglioside-binding proteins in membrane lysates of adult rat cerebellum. Three proteins (p58, p90, and p160) were identified as GT1b-binding proteins by incubation of the blot of the membrane lysate with GT1b micelles. We generated a monoclonal antibody (mAb) specific to the polypeptide portion of the GT1b-binding proteins (YAK-2). The YAK-2 mAb specifically reacted with all three proteins on blots of proteins pretreated under nonreducing conditions for SDS-PAGE, but reacted mainly with p58 under reducing conditions, showing that p90 and p160 are oligomeric forms of p58. The binding activity of the YAK-2 mAb was completely inhibited by the presence of GT1b micelles, indicating the specificity of YAK-2 mAb for p58 and its oligomers. Immunohistochemical investigations revealed that both p58 and GT1b colocalize within the granular layer of adult rat cerebellum. Expression cloning of p58 cDNA was performed using YAK-2 mAb, and five putative clones were obtained. Among them, the nucleotide sequence of one cDNA completely matched that of rat brain-specific sodium-dependent inorganic phosphate cotransporter (rBNPI), a 61 kDa membrane protein. COS7 cells were transfected with a Flag-chimeric construct containing the rBNPI/p58 cDNA, and the membrane lysate was subjected to immunoprecipitation with anti-Flag antibody. One protein (64 kDa) was detected only with YAK-2 mAb, and the membrane lysate specifically bound to GT1b micelles. Taking together, we propose that rBNPI/p58 functions as a GT1b-binding protein in neuronal cells. 相似文献
45.
Shimoda LA Sham JS Shimoda TH Sylvester JT 《American journal of physiology. Lung cellular and molecular physiology》2000,279(5):L884-L894
In the lung, chronic hypoxia (CH) causes pulmonary arterial smooth muscle cell (PASMC) depolarization, elevated endothelin-1 (ET-1), and vasoconstriction. We determined whether, during CH, depolarization-driven activation of L-type Ca(2+) channels contributes to 1) maintenance of resting intracellular Ca(2+) concentration ([Ca(2+)](i)), 2) increased [Ca(2+)](i) in response to ET-1 (10(-8) M), and 3) ET-1-induced contraction. Using indo 1 microfluorescence, we determined that resting [Ca(2+)](i) in PASMCs from intrapulmonary arteries of rats exposed to 10% O(2) for 21 days was 293.9 +/- 25.2 nM (vs. 153.6 +/- 28.7 nM in normoxia). Resting [Ca(2+)](i) was decreased after extracellular Ca(2+) removal but not with nifedipine (10(-6) M), an L-type Ca(2+) channel antagonist. After CH, the ET-1-induced increase in [Ca(2+)](i) was reduced and was abolished after extracellular Ca(2+) removal or nifedipine. Removal of extracellular Ca(2+) reduced ET-1-induced tension; however, nifedipine had only a slight effect. These data indicate that maintenance of resting [Ca(2+)](i) in PASMCs from chronically hypoxic rats does not require activation of L-type Ca(2+) channels and suggest that ET-1-induced contraction occurs by a mechanism primarily independent of changes in [Ca(2+)](i). 相似文献
46.
47.
Involvement of jasmonate- and salicylate-related signaling pathways for the production of specific herbivore-induced volatiles in plants 总被引:25,自引:0,他引:25
We compared volatiles from lima bean leaves (Phaseolus lunatus) infested by either beet armyworm (Spodoptera exigua), common armyworm [Mythimna (Pseudaletia) separata], or two-spotted spider mite (Tetranychus urticae). We also analyzed volatiles from the leaves treated with jasmonic acid (JA) and/or methyl salicylate (MeSA). The volatiles induced by aqueous JA treatment were qualitatively and quantitatively similar to those induced by S. exigua or M. separata damage. Furthermore, both S. exigua and aqueous JA treatment induced the expression of the same basic PR genes. In contrast, gaseous MeSA treatment, and aqueous JA treatment followed by gaseous MeSA treatment, induced volatiles that was qualitatively and quantitatively more similar to the T. urticae-induced volatiles than those induced by aqueous JA treatment. In addition, T. urticae damage resulted in the expression of the acidic and basic PR genes that were induced by gaseous MeSA treatment and by aqueous JA treatment, respectively. Based on these data, we suggest that in lima bean leaves, the JA-related signaling pathway is involved in the production of caterpillar-induced volatiles, while both the SA-related signaling pathway and the JA-related signaling pathway are involved in the production of T. urticae-induced volatiles. 相似文献
48.
Induced Response of Tomato Plants to Injury by Green and Red Strains of Tetranychus Urticae 总被引:1,自引:0,他引:1
Takabayashi J Shimoda T Dicke M Ashihara W Takafuji A 《Experimental & applied acarology》2000,24(5-6):377-383
We studied the induced response of tomato plants to the green strain and the red strain of the spider mite Tetranychus urticae. We focused on the olfactory response of the predatory mite Phytoseiulus persimilis to volatiles from T. urticae-infested tomato leaves in a Y-tube olfactometer. Tomato leaves attracted the predatory mites when slightly infested with the red strain, or moderately or heavily infested with the green strain. In contrast, neither leaves that were slightly infested with green-strain mites, nor leaves that were moderately or heavily infested with the red strain attracted the predators. We discuss the specific defensive responses of tomato plants to each of the two strains. 相似文献
49.
50.
Yosuke Hamamoto Hiromu Ito Moritoshi Furu Motomu Hashimoto Takao Fujii Masahiro Ishikawa Noriyuki Yamakawa Chikashi Terao Masayuki Azukizawa Takahiro Iwata Tsuneyo Mimori Shuichi Matsuda 《PloS one》2015,10(8)