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41.
Midori Kobayakawa 《Ichthyological Research》1989,36(2):155-186
On the basis of external morphology and anatomy, 17 scpeies of the genusSilurus Linnaeus including a new species,S. torrentis from Thailand and Burma, are recognized as valid.S. bedfordi Regan is synonymized withS. asotus, andS. goae Haig is transferred to the genusOmpok. From an anatomical study of 12 species, the diagnostic feature of the genusParasilurus Bleeker is revealed to be invalid, and the genus is synonymized withSilurus. From the phylogenetic analysis, the genusSilurus is divided into two major species groups, thecochinchinensis group which is disributed mainly in Southeast Asia, and theglanis group which is further separated into three subgroups occurring separately in East Asia and Europe. The pattern of distribution
and relationships between ontogeny and phytogeny in the genusSilurus are briefly discussed. 相似文献
42.
The reaction to C-banding was investigated throughout the mitotic cycle ofCrepis capillaris (2n=6): (1) 18–22 C-bodies or C-bands were found during mid telophase and interphase to prophase and metaphase, and also
12–14 at late anaphase to early telophase in the mitotic cycle. Fewer C-bands in late anaphase to early telophase were due
to the absence of minute bands; (2) large and medium sized C-bands were strongly stained by Giemsa, while small and minute
bands stained palely. It is suggested that inCrepis capillaris the difference of color in C-banded segments following Giemsa staining is referable to the amount of constitutive heterochromatin
rather than to the difference in the condensation and decondensation; (3) the size of C-bodies changed during telophase to
interphase and prophase. It is inferred that the extent of C-bodies is regulated by both the length of DNA sequences of constitutive
heterochromatin and the amount of proteins combined with C-banded DNA. It was shown that the reaction to C-banding is neither
due to the differential condensation of chromatin nor to a higher concentration of DNA in the C-banded regions, in the C-banding
mechanism as has been suggested so far at least. 相似文献
43.
Midori Hiramatsu Kumiko Haba Rei Edamatsu Hajime Hamada Akitane Mori 《Neurochemical research》1989,14(3):249-251
The effect of a Chinese herbal medicine Sho-saiko-to-go-keishi-ka-shakuyaku-to (TJ-960) on the brain choline acetyltransferase (CAT) activity was studied in adult (3.5 months of age) and aged (24 months of age) rats. After oral administration of 5% TJ-960 solution for 3 months, CAT activity in the hippocampus, pons-medulla oblongata and striatum of aged rats was significantly lower than that of adult rats. CAT activity in the cerebellum, however, was significantly higher in the aged rats, as compared to the adult rats. TJ-960 significantly increased CAT activity in the hippocampus and striatum of aged rats, but did not affect the activity of the enzyme in the adult rat brain. 相似文献
44.
Nucleotide sequence of the chromosomal gene coding for the aminoglycoside 6-adenylyltransferase from Bacillus subtilis Marburg 168 总被引:2,自引:0,他引:2
Gene aadK of Bacillus subtilis is 855 bp long and codes for aminoglycoside 6-adenylyltransferase. 相似文献
45.
46.
The cell cycle block and lysis of an activated T cell hybridoma are distinct processes with different Ca2+ requirements and sensitivity to cyclosporine A 总被引:13,自引:0,他引:13
M Mer?ep P D Noguchi J D Ashwell 《Journal of immunology (Baltimore, Md. : 1950)》1989,142(11):4085-4092
Stimulation of transformed T cells leads to both lymphokine secretion and inhibition of spontaneous growth. Studies performed with an Ag-specific T cell hybridoma demonstrated that growth inhibition is an early (within 1 h) manifestation of activation. Experiment in which extracellular Ca2+ was chelated or in which cyclosporine A was included indicated that activation-associated growth inhibition is a two-step process. The first phase is the establishment of a G1/S cell cycle block; it does not require extracellular Ca2+ and is not prevented by the addition of cyclosporine A. The second phase is cell lysis. It can be detected 4 to 6 h after activation, requires the presence of extracellular Ca2+, and is prevented when stimulation occurs in the presence of cyclosporine A. The observation that both Ca2+ depletion and cyclosporine A prevented IL-2 secretion at all time points indicates that the pathways leading to lymphokine secretion and the G1/S block diverge early in the course of the cellular response, and establish the cell cycle block as a distinct activation event with unique characteristics. 相似文献
47.
48.
The sre gene (ORF469) encodes a site-specific recombinase responsible for integration of the R4 phage genome. 总被引:3,自引:0,他引:3
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M Matsuura T Noguchi D Yamaguchi T Aida M Asayama H Takahashi M Shirai 《Journal of bacteriology》1996,178(11):3374-3376
The sre gene (ORF469) of the R4 phage encodes a protein similar to the resolvase-DNA invertase family proteins. Insertional gene disruption of sre prevented a lysogen from entering the lytic cycle, implying that Sre protein is a site-specific recombinase needed for excision of the R4 prophage genome (M. Matsuura, T. Noguchi, T. Aida, M. Asayama, H. Takahashi, and M. Shirai, J. Gen. Appl. Microbiol. 41:53-61, 1995). To determine whether this sre gene is also necessary for the integration reaction, we studied its function by integration plasmid analysis. When deletions, frameshifts, and site-directed mutations that caused an amino acid substitution of Ser-17 for Ala were introduced into the sre structural gene, transformation efficiency of Streptomyces parvulus 2297 with these plasmid DNAs was severely reduced. However, an adenine insertion just before the possible initiation codon of the sre gene did not significantly decrease the efficiency. These data suggest that the Sre protein is a site-specific recombinase responsible for integration of the R4 phage genome. 相似文献
49.
Yuichi Murayama Ryozaburo Mukai Tetsutaro Sata Satoko Matsunaga Atsuo Noguchi Yasuhiro Yoshikawa 《Microbiology and immunology》1996,40(6):467-471
In contrast to the case of peripheral T cells, the surface expression of CD20 antigen and the expression of CD20 mRNA in monkey lymph node (LN) T cells underwent a noticeable increase when they were cultured with mitogen and interleukin-2 (IL-2). To confirm in vivo regulation of CD20 expression during the activation of LN T cells, we examined LNs derived from monkeys experimentally inoculated with simian immunodeficiency virus (SIV). Significant expression of CD20 antigen was detected in the T cells of the LNs at the stage of lymphadenopathy. These findings suggest that lymphocyte activation in the LNs induced expression of the CD20 molecule in some T cells. 相似文献
50.
Dis3, implicated in mitotic control, binds directly to Ran and enhances the GEF activity of RCC1. 总被引:9,自引:0,他引:9
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E Noguchi N Hayashi Y Azuma T Seki M Nakamura N Nakashima M Yanagida X He U Mueller S Sazer T Nishimoto 《The EMBO journal》1996,15(20):5595-5605
Using the two-hybrid method, we isolated a Saccharomyces cerevisiae cDNA encoding a protein homologous to Schizosaccharomyces pombe protein Dis3sp, using as bait, human GTPase Ran. The DIS3 gene is essential for viability and complements S.pombe mutant dis3-54 which is defective in mitosis. Although Dis3sc has no homology to RanBP1, it bound directly to Ran and the S.cerevisiae Ran homologue Cnr1, but not to the S.cerevisiae RCC1 homologue Srm1. Upon binding to Ran with a 1:1 molar ratio, Dis3sc enhanced a nucleotide-releasing activity of RCC1 on Ran. In the presence of Dis3sc, the K(m) of RCC1 on Ran decreased by half, while the kcat was unchanged. In vivo, Dis3sp was present as oligomers of M(r) 670-200 kDa as previously reported, and the 200 kDa oligomer of Dis3sp was found to include Spi1 and Pim1, the S.pombe homologues of Ran and RCC1, respectively. Although the biological function of the heterotrimeric oligomer consisting of Dis3, Spi1 and Pim1 is unknown, our results indicate that Dis3 is a component of the RCC1-Ran pathway. 相似文献