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2.
Summary Transgenic cucumber (Cucumis sativus L.) plants were successfully obtained from hypocotyl explants inoculated with Agrobacterium tumefaciens, which harbored a binary vector plasmid with NOS-nptII, CaMV 35S-I-gus and CaMV 35S-hph genes. Acetosyringone enhanced the efficiency of transformation at the cut surface cells of hypocotyl explants during five days of co-cultivation. Transformed cells were more effectively selected using 20–30 mg/l hygromycin B than using 50–100 mg/l kanamycin. Shoot regeneration occurred within 4–6 wks, and 12 of 21 regenerated plantlets displayed strong GUS expression in the very young leaves. All of 8 GUS-positive R0 plants examined showed single or a few positive bands by Southern blot analysis. The expression of the CaMV 35S-I-gus gene was observed in various tissues and organs of R0 and R1 transgenic cucumber plants. 相似文献
3.
Susumu Ikegami Yasunori Ooe Takahiko Shimizu Toshihiko Kasahara Tatsuhiko Tsuruta Masako Kijima Minoru Yoshida Teruhiko Beppu 《Development genes and evolution》1993,202(3):144-151
Summary External application of 10 rig/ml (R)-trichostatin A (TSA), a potent and specific inhibitor of mammalian histone deacetylase, to the embryo of the starfish Asterina pectinifera inhibited development during the early gastrula stage before formation of mesenchyme cells. The TSA-sensitive period was limited to the mid-blastula stage before hatching. The pulse-chase experiment clearly demonstrated that TSA induced an accumulation of acetylated histone species in blastulae through inhibition of historic deacetylation. Similar blockage of development at the early gastrula stage was observed with n-butyrate, which has been known as a weak inhibitor of historic deacetylase. These results suggest an intimate role for historic acetylation-deacetylation equilibria in starfish development.
Correspondence to: S. Ikegami 相似文献
4.
Yoshihiro Takasugi Keiji Kawata Takahiko Okuda Yoshihisa Koga Nobuyuki Mizuguchi Shigeaki Yamanaka Shinsuke Watanabe 《Experimental Animals》2003,52(5):429-432
Age-related alterations and differences of weights and those of amino acid concentrations in the cerebrospinal fluid (CSF) were evaluated between Sprague Dawley (SD) rats and Wistar Kyoto (WKY) rats from eight to twenty weeks of age. The weights of SD rats were heavier than WKY rats at all ages. The age-related alterations of the CSF concentration of many amino acids within each strain were significant but showed no significant trend with age. Between the strains, the concentration differences of excitatory and inhibitory amino acids were not frequent although the concentrations of arginine, alanine and threonine were significantly higher in SD rats than in WKY rats. These results suggest that the different CSF concentrations of amino acids may relate to characteristics of rat strains. 相似文献
5.
Kazuto Nunomura Satoru Kawakami Takahiko Shimizu Tomohiro Hara Kazuhiro Nakamura Yudai Terakawa Akiko Yamasaki Susumu Ikegami 《European journal of biochemistry》2003,270(18):3750-3759
A histone heterodimer, designated as p28, which contains an Nepsilon(gamma-glutamyl)lysine cross-link between Gln9 of histone H2B and Lys5 or Lys12 of histone H4, is present in starfish (Asterina pectinifera) sperm. Treatment of sperm nuclei with micrococcal nuclease produced soluble chromatin, which was size-fractionated by sucrose-gradient centrifugation to give p28-containing oligonucleosome and p28-free mononucleosome fractions, indicating that the cross-link is internucleosomal. When sperm nuclei were incubated with monodansylcadaverine, a fluorescent amine, in the presence or absence of Ca(2+), histone H2B was modified only in the presence of Ca(2+). Gln9, in the N-terminal region, was modified, but the other Gln residues located in the internal region were not, suggesting that the modification takes place on the surface of the nucleosome core by the in situ action of a Ca(2+)-dependent nuclear transglutaminase. Treatment of sperm with the egg jelly, which activates Ca(2+) influx to induce the acrosome reaction, resulted in a significant elevation of the p28 content in the nucleus. This is the first demonstration of an in vivo activation of transglutaminase leading to the formation of a cross-link in intracellular proteins. 相似文献
6.
Tetsuya Tanigawa Yasuo Mizo-oku Kouichi Moriguchi Takashi Suzuki Takahiko Osumi Masaaki Odomi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,683(2):135
A simple and rapid quantitative method for 13C-labelled urea ([13C]urea) in human serum was developed by using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS). This method is used to establish and normalize the [13C]urea breath test, which is considered as an effective diagnostic method for Helicobacter pylori infection. HPLC-APCI-MS, involving a simple pretreatment process such as diluting serum with water, was shown to be able to discriminate the extrinsic [13C]urea from intrinsic urea present at high concentration in serum. In addition, a 13C nuclear magnetic resonance spectroscopic quantitative method for [13C]urea in human urine is also described. The precision and accuracy of measured concentrations in these two methods were found to be within the acceptable limit. An application of these methods to investigate the pharmacokinetic profile of orally administered [13C]urea in human serum and urine is also presented. 相似文献
7.
Some properties of the circadian rhythm in potassium uptakeof flow medium culture of the long-day duckweed Lemna gibbaG3 were examined.
- In total darkness, the rhythm faded out in ca. 48 hr; it restartedon transfer to continuous light. Under low-intensity light (below700 lux), the rhythm was damped rapidly
- The rhythm appearedregardless of the potassium concentrationin the culture medium(from 10/m to 2 HIM). The amplitude, butnot the period, ofthe rhythm was influenced by the ambientpotassium concentration.
- Alteration in the light intensity or medium composition causeda change in the growth rate without modifying the period ofthe rhythm.
- These results indicate that potassium uptake rhythmin thisduckweed is typical light-on rhythm, which has no directrelationwith the rate of vegetative growth and requires lightenergyfor its duration.
8.
The potassium uptake activity of the "flow-medium culture" ofa long-day duckweed, Lemna gibba G3, followed a circadian rhythmwhich persisted for more than 5 days under continuous light.The period of the rhythm was about 25 hr under 3000 lux at 26?Cand was slightly over-compensated against temperature, Q10 beinga little less than 1.0. The amplitude of the rhythm was dependenton light intensity, and there was no potassium uptake in thedark. Magnesium uptake was affected by the potassium movementand showed circadian rhythmicity with a small amplitude underconditions where the potassium uptake was already saturated.Calcium uptake did not show any obvious rhythm. In Contrastto L. gibba, a short-day duckweed L. perpusilla 6746 displayedcircadian rhythm of potassium uptake only in the dark and notin the light. This rhythm did not persist beyond the secondcycle. (Received June 13, 1978; ) 相似文献
9.
Takahiko Tanaka Steven R. Vincent George G. Nomikos Hans C. Fibiger 《Journal of neurochemistry》1992,59(5):1640-1645
In vivo brain microdialysis was used to examine the role of potassium channel activation in dopamine (DA) autoreceptor function in the striatum of freely moving rats. Local application of the D2 receptor agonists quinpirole or N-0437 through the dialysis probe significantly reduced extracellular concentrations of DA. Local application of the D2 antagonist (-)-sulpiride produced significant increases in DA. Local perfusion with quinine, a K+ channel blocker, completely blocked the (-)-sulpiride-induced increases in DA but did not affect the DA agonist-induced decreases. (-)-Sulpiride completely blocked the effect of quinpirole on DA both in control and in quinine-treated animals. At the highest dose used, quinine caused a large transient increase in extracellular DA. Local application of tetrodotoxin or infusion of Mg2+ in the absence of Ca2+ did not prevent this quinine-induced transient increase in extracellular DA. These results demonstrate that DA autoreceptors in the striatum regulate DA release in awake, behaving animals. Local application of (-)-sulpiride increases DA levels by blocking the tonic activation of autoreceptors by endogenous DA. Quinine blocks the neuroleptic-induced increase in DA, perhaps by preventing the K+ channel opening that would normally accompany endogenous autoreceptor activation. The fact that exogenously applied DA receptor agonists can decrease extracellular DA levels in the presence of quinine suggests that they may be acting at extrasynaptic autoreceptors that are not tonically active in vivo. The effect of DA agonists on this site is via a DA receptor because it is blocked by (-)-sulpiride. However, this receptor does not appear to be coupled to a quinine-sensitive potassium channel. 相似文献