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981.
Synopsis We observed the behavior of the spawning group of Japanese sardine,Sardinops melanostictus, in the field at night, and also confirmed the spawning behavior in the darkness in captivity. The chasing and mating were done in a pair of 1 male and 1 female. The 1-to-1 mating was a definite finding irrespective of the group density in the field, the density in the tank in captivity, or the sex ratio. This maybe because there is little visual information during spawning at night. 相似文献
982.
983.
Apoptosis induced by selenium in human glioma cell lines 总被引:8,自引:0,他引:8
Zongjian Zhu Mieko Kimura Yoshinori Itokawa Tomokazu Aoki Jun A. Takahashi Shouji Nakatsu Yoshifumi Oda Haruhiko Kikuchi 《Biological trace element research》1996,54(2):123-134
Several studies have shown that selenium can inhibit tumorigenesis in tissues. However, little is known about the mechanism
and the effect of selenium on DNA, especially in brain tumor cells. In this study we examined the biological effect of selenium
on human glioma cell lines (A172 and T98G). Selenium exhibited an antiproliferative effect on these cell lines (and induced
the typical ladder pattern of DNA fragmentation commonly found in apoptosis), which were prevented by catalase. Few effects
of selenium on NTI4 fibroblasts were found. These findings demonstrate that selenium may induce, by apoptosis, cell death
of human glioma cell lines, which are resulting from free radical oxygen forming. 相似文献
984.
Circadian expression of the dnaK gene in the cyanobacterium Synechocystis sp. strain PCC 6803.
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The expression of the dnaK gene in the cyanobacterium Synechocystis sp. strain PCC 6803 was continuously monitored as bioluminescence by an automated monitoring system, using the bacterial luciferase genes (luxAB) of Vibrio harveyi as a reporter of promoter activity. A dnaK-reporting bioluminescent Synechocystis strain was constructed by fusing a promoterless segment of the luxAB gene set downstream of the promoter region of the Synechocystis dnaK gene and introduction of this gene fusion into a BglII site downstream of the ndhB gene in the Synechocystis chromosome. Bioluminescence from this strain was continuously monitored and oscillated with a period of about 22 h for at least 5 days in continuous light. The phase of the rhythm was reset by the timing of the 12-h dark period administered prior to the continuous light. The period of the rhythm was temperature compensated between 25 and 35 degrees C. Thus, the bioluminescence rhythm satisfied the three criteria of circadian rhythms. Furthermore, the abundance of dnaK mRNA also oscillated with a period of about 1 day for at least 2 days in continuous light conditions, indicating circadian control of dnaK gene expression in Synechocystis sp. strain PCC 6803. 相似文献
985.
The major triterpenoids in both the female and male flowers of Alnus sieboldiana are a C31-secodammarane-type, alnustic acid, and its 12-O-α-L-arbinofuranoside and 12-O-β-D-xylopyranoside. 相似文献
986.
Six C31-secodammarane-type triterpenoid saponins, in addition to alnustic acid, were isolated from the male flowers of Alnus pendula. Two of these saponins were new and were shown to be the 12-O-(2′-O-acetyl)-β-d-xylopyranoside and the 12-O-(2′-O-acetyl)-β-d-glucopyranoside of alnustic acid, respectively, on the basis of their physico-chemical data. 相似文献
987.
Abstract: Intrageneric relationships in the genus Nicotiana were investigated by comparison of DNA sequences of the matK gene of the chloroplast genome. A total of 40 taxa were examined in this study, representing 39 of the approximately 70 wild species of this genus. We obtained the full sequences of the 1530 bp matK ORFs; no variations in length due to insertions or deletions were found. The phylogenetic trees obtained from maximum parsimony (MP) and neighbour-joining (NJ) methods were fundamentally consistent. The genus Nicotiana formed a clade in these trees. The traditional classification of this genus was mostly in agreement with the molecular phylogeny. However, all three subgenera and some sections did not form a monophyletic group. Character-state mappings were used to infer a centre of origin, biogeographic history, and transition of chromosome number. The results support the previous hypothesis that this genus originated in South America and subsequently spread to other continents. The suggestion that the ancestral basic chromosome number is x = 12 and that polyploidy and aneuploidy have occurred independently several times during the evolution of Nicotiana species is also discussed. 相似文献
988.
A Fuse Y Aoki T Sato M Kita T Yamamoto K Toriizuka M Sunohara H Takeoka 《Biological Sciences in Space》2001,15(3):302-303
It is reported that the stay in the space develops anemia, thrombocytopenia, and altered function and structure of red blood cell. The mechanism of these abnormalities was not clarified yet. The cloning of the thrombopoietin (TPO), followed by the analysis of TPO and c-mpl (its cellular receptor) knockout mice confirmed its role as the primary regulator of thrombopoiesis. TPO has been shown to stimulate both megakaryocyte colony growth from marrow progenitor cells and the maturation of immature megakaryocyte to form functional platelet. This process includes the massive cytoskeletal rearrangement, such as proplatelet formation and fragmentation of proplatelet. In this study we have focused on the production of thrombopoietic growth factors in mice those were exposed to gravity change by parabolic flight (PF). 相似文献
989.
Stress Protein Inductions After Brain Ischemia 总被引:7,自引:0,他引:7
K. Abe J. Kawagoe M. Aoki K. Kogure Y. Itoyama 《Cellular and molecular neurobiology》1998,18(6):709-719
990.
Mayumi Kijima-Tanaka Masayuki Nakamura Noriyuki Nagamine Toshio Takahashi Akemi Aoki Yutaka Tamura 《FEMS immunology and medical microbiology》1994,8(3):183-187
Abstract Polyclonal rabbit anti-idiotypic antibody (anti-Id) against the protective monoclonal antibody specific to the flagella of Clostridium chauvoei was produced, purified, and characterized. Anti-Id inhibited the binding of its related monoclonal antibody to the flagellar antigen, suggesting that the anti-Id bore an internal image of the flagellar antigen. When mice were immunized with anti-Id intraperitoneally, the survival rate increased significantly, compared with mice immunized with normal rabbit IgG ( P < 0.01), and specific anti-flagellar antibodies were induced. 相似文献