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41.
The soybean embryo factor binding sequence in the glycinin A2B1a gene promoter was delimited to an A/T-rich 9 bp sequence, 5-TAATAATTT-3, designated as the glycinin box, by DNA footprinting and gel mobility shift assay using synthetic oligonucleotides. It was shown that the interaction with the factor takes place at a defined DNA sequence rather than at random A/T-rich sequence blocks in the glycinin 5 flanking region. There are four glycinin boxes in the quantitative regulatory region between positions – 545 and – 378 of the glycinin A2B1a promoter. Multiple nonamer motifs similar to the glycinin box were also found in the equivalent regions of other glycinin and legumin promoters, suggesting that they must be conserved as a binding site for the embryo factor that activates the differential and stage-specific expression of seed 11S globulin genes in leguminous plants. 相似文献
42.
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44.
Leptocephalus eel larvae will feed in aquaria 总被引:1,自引:0,他引:1
Synopsis Premetamorphosing larvae of Muraenesox cinereus (Muraenesocidae) and Conger myriaster (Congridae), caught and kept alive in aquaria, repeatedly bit pieces out of a lump of squid paste. By coloring the paste with Brilliant Red, ingestion and defecation were clearly seen through the transparent gut. The paste is not their natural food, but nevertheless a possible food item for rearing eels from eggs; most previous efforts have failed inasmuch as the larvae have starved. 相似文献
45.
Production of berberine could be induced by adding 6-benzylaminopurine (BAP) to Thalictrum minus cells, cultured in suspension in a medium containing 2,4-dichlorophenoxyacetic acid (2,4-D), early in the growth cycle. In the presence of BAP, the precursor, L-tyrosine, was rapidly converted into berberine which was then released into the medium, whereas substantial amounts of the intermediates, tyramine and dopamine, accumulated in non-berberine-producing cells grown in the same 2,4-D-containing medium without BAP. These results suggest that BAP activated enzymatic reactions subsequent to the formation of the amines in the biosynthesis of berberine.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- BAP
6-benzylaminopurine
- NAA
1-naphthaleneacetic acid
- IAP
6-isopentenylaminopurine
- LS medium
Linsmaier-Skoog medium
- Growth medium
LS medium containing 10-6 M 2,4-D 相似文献
46.
Shingo Oda Masashi Shibata Toshio Moritani 《Journal of electromyography and kinesiology》1996,6(4):247-252
The purpose of this study was to compare movement-related cortical potentials (MRCPs) associated with different levels of isometric contractions by elbow flexors. Eight healthy, right-handed male subjects participated in this study and performed different levels (10 and 50% of maximal voluntary contraction) of isometric contractions by the right elbow flexors. Electroencephalogram (EEG) signals were recorded from Fz, C3, Cz and C4 of the international 10/20 system. Motor potential (MP) amplitudes (from −200 to approximately −50 ms before force onset) for C3 associated with both force generations was significantly greater (P < 0.01) than those for C4, indicating that contralateral predominance of MRCP was observed in the right arm flexion. In Fz, the potentials of negative slope (NS′) (from −600 to approximately −200 ms) and MPs for 50% MVC were significantly greater than those of 10% MVC. In Cz, the MP associated with 50% MVC revealed a significantly greater (P < 0.05) value than that with 10% MVC. In C3 and C4, the MP associated with 50% MVC tended to be greater than that with 10% MVC, but no statistically significant differences were found. These force-dependent changes in MRCPs imply increased activation of neural circuits involved in motor preparation and initiation. It is therefore suggested that the larger potentials from Fz and Cz for 50% MVC compared with 10% MVC reflect a greater activation of supplementary motor area for the preparation of the larger force generation. 相似文献
47.
Cells of Nitella flexilis were made inexcitable by treatmentwith 10 mM KCl for more than 24 h. A Ca2+-sensitive photoproteinaequorin was injected into the cytoplasm of such cells. Forvacuolar per fusion, the central part of an aequorin-loadedcell was immersed in silicone oil, and both cell ends bathedin the perfusion medium were cut off. A large light emissionfrom aequorin was observed when the vacuole was perfused witha hypotonic medium whose osmotic pressure was adjusted to halfof the osmotic pressure of the cell sap. This shows that hydrationof the cytoplasm triggers release of Ca2+ from internal stores,since influx of Ca2+ from silicone oil is excluded. Hydration of cells was induced in another way. Cells were firstdehydrated by transferring them from 10 mM KCl solution to thatwith 250 mM sorbitol added. This procedure did not affect thecytoplasmic streaming. When cells were rehydrated by transferringthem to 10 mM KCl solution, cytoplasmic streaming was eitherstopped or slowed down in a few seconds. A quick light emissionfrom aequorin was observed in the rehydration, evidence thatcytoplasmic streaming was inhibited by an increase in the cytoplasmicCa2+ concentration. Both streaming cessation and aequorin lightemission were observed even in KCl-treated cells which werefurther treated with 5 mM EGTA. Thus, the increase in Ca2+ isconcluded to be caused by the release of Ca2+ from internalstores. These results support our previous hypothesis [Tazawa et al.(1994) Plant Cell Physiol. 35:63] that, in Nitella flexilis,the increase in the concentration of Ca2+ in the cytoplasm whichoccurs on the endoosmotic side of the cell during transcellularosmosis is caused by hydration of the cytoplasm. (Received June 6, 1994; Accepted December 26, 1994) 相似文献
48.
Seitaro Ohkuma Hidehiko Narihara Masashi Katsura Takeshi Hasegawa Kinya Kuriyama 《Journal of neurochemistry》1995,65(3):1109-1114
Abstract: The functional significance of peroxynitrite in the release of [3 H]GABA induced by nitric oxide (NO) liberated from NO generators was investigated using cerebral cortical neurons in primary culture. NO generators such as sodium nitroprusside (SNP) and S -nitroso- N -acetylpenicillamine (SNAP) increased [3 H]GABA release in a dose-dependent manner. These increases in [3 H]GABA release were significantly inhibited by hemoglobin, indicating that those NO generators evoke the release of [3 H]GABA by the formation of NO. Two types of superoxide scavengers, Cu2+ /Zn2+ superoxide dismutase and ceruloplasmin, significantly reduced the increase in [3 H]GABA release induced by both SNP and SNAP, which assumes that NO requires superoxide to induce [3 H]GABA release from the neurons. In addition, synthesized peroxynitrite induced a dose-dependent increase in [3 H]GABA release from the neurons. These results indicate that NO-induced [3 H]GABA release is mediated by peroxynitrite formed by the reaction of NO with superoxide. 相似文献
49.
Alexander A. Bachmanov Danielle R. Reed Yuro Ninomiya Masashi Inoue Michael G. Tordoff R. Arlen Price Gary K. Beauchamp 《Mammalian genome》1997,8(8):545-548
Individual variability in sucrose consumption is prominent in humans and other species. To investigate the genetic contribution
to this complex behavior, we conducted behavioral, electrophysiological, and genetic studies, using male progeny of two inbred
mouse strains (C57BL/6ByJ [B6] and 129/J [129]) and their F2 hybrids. Two loci on Chromosome (Chr) 4 were responsible for over 50% of the genetic variability in sucrose intake. These
loci apparently modulated intake by altering peripheral neural responses to sucrose. One locus affected the response threshold,
whereas the other affected the response magnitude. These findings suggest that the majority of difference in sucrose intake
between male B6 and 129 mice is due to polymorphisms of two genes that influence receptor or peripheral nervous system activity.
Received: 27 January 1997 / Accepted: 17 March 1997 相似文献
50.
T. Ito Naoko Udaka Yoshiaki Inayama Hitoshi Kitamura Masayoshi Kanisawa 《Histochemistry and cell biology》1997,109(1):67-73
We have examined the distribution of calcium-binding proteins (CaBPs) in adult and fetal lungs of Syrian golden hamsters
(Mesocricetus auratus) using immunostaining with confocal laser microscopy and electron microscopy. Single and grouped (neuroepithelial body; NEB)
endocrine cells were distributed from bronchi to alveolar ducts in the adult lung. Serial frozen sections immunostained for
CaBPs in combination with immunostaining for endocrine markers such as calcitonin gene-related peptide, serotonin, PGP9.5,
and synaptophysin revealed that positive immunostaining for calbindin-D28K (CB-D28K) was seen in single endocrine cells and NEBs. However, other so-called EF-hand family CaBPs, parvalbumin and calretinin,
were not detected. Electron microscopically, positive immunoreaction for CB-D28K was mainly in the organelle-free cytoplasmic
matrix of endocrine cells, and partly in nuclei and associated with secretory granules and endoplasmic reticulum. In fetal
developing lungs, endocrine cells appeared first on gestational day 13, and they were positive for all the endocrine markers
used. However, pulmonary endocrine cells were positively immunostained for CB-D28K from gestational days 15 and 16 onward.
In summary, our observations suggest that CB-D28K is a useful marker for endocrine cells of the lung, and CB-D28K could function
as a mediator of endocrine stimulation or calcium homeostasis in pulmonary endocrine cells.
Accepted: 17 June 1997 相似文献