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61.
Carbon use efficiencies (gram cell organic dry weight accumulated per gram sugar assimilated from the medium) of unadapted and NaCl-adapted (428 millimolar) cells of tobacco (Nicotiana tabacum L. var Wisconsin 38) were determined to evaluate metabolic costs associated with growth and survival in a saline environment. No net increase in carbon costs was associated with salt adaptation. At low substrate levels, carbon use efficiencies of unadapted and NaCl-adapted cells were not appreciably different (0.495 and 0.422, respectively) and at higher substrate levels carbon use efficiency of NaCl-adapted cells was clearly higher than that of unadapted cells. These results indicate that a homeostasis of metabolic efficiency is established after cells have adapted to NaCl. Altered carbon availability does not cause the reduced cell volume that results from adaptation to NaCl. This does not preclude, however, the possibility that altered intracellular partitioning of carbon affects cell expansion. 相似文献
62.
H Hasegawa 《The Journal of parasitology》1989,75(6):863-869
Uncinaria (Uncinaria) maya n. sp. (Nematoda: Ancylostomatidae) and Molineus springsmithi yayeyamanus n. subsp. (Nematoda: Molineidae) are described from the Iriomote cat, Prionailurus iriomotensis, on Iriomote Island, Okinawa, Japan. Uncinaria (U.) maya resembles Uncinaria (Uncinaria) felidis Maplestone, 1939, from Prionailurus bengalensis of India but is distinguished in that the body is much smaller, the ventral rays are set closely with the lateral rays, and the externolateral ray is much shorter than other laterals. Molineus springsmithi yayeyamanus differs from Molineus springsmithi springsmithi Inglis and Ogden, 1965, from Prionailurus bengalensis horsfieldi of East Nepal in that the body is much longer, whereas the esophagus is somewhat shorter and the spicules are divided more distally. Presence of the closely related nematodes in both the Iriomote cat and P. bengalensis suggests a close evolutionary relationship of the 2 hosts. 相似文献
63.
Hideko Yamamoto-Otake Asahi Matsuyama Eiichi Nakano 《Applied microbiology and biotechnology》1990,33(6):680-682
Summary A phosphotransacetylase gene (pta) has been cloned from a genomic DNA library ofEscherichia coli 1100, a derivative of strain K-12. The phosphotransacetylase activities ofpta
+ plasmid-containing strains were amplified about 150-fold under control of thelac promoter. The molecular weight of the phosphotransacetylase was estimated to be about 81,000 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Thepta gene was found to be downstream ofackA by a combination of restriction analysis and plasmid subcloning. It is located about 13 kb upstream of thepurF-folC-hisT region of the chromosome. 相似文献
64.
Takashi Kamaishi Tetsuo Hashimoto Yoshihiro Nakamura Fuminori Nakamura Shigenori Murata Norihiro Okada Ken-ichi Okamoto Makoto Shimizu Masami Hasegawa 《Journal of molecular evolution》1996,42(2):257-263
Partial regions of the mRNA encoding a major part of translation elongation factor 1 (EF-1) from a mitochondrion-lacking protozoan,Glugea plecoglossi, that belongs to microsporidians, were amplified by polymerase chain reaction (PCR) and their primary structures were analyzed. The deduced amino acid sequence was highly divergent from typical EF-1's of eukaryotes, although it clearly showed a eukaryotic feature when aligned with homologs of the three primary kingdoms. Maximum likelihood (ML) analyses on the basis of six different stochastic models of amino acid substitutions and a maximum parsimony (MP) analysis consistently suggest that among eukaryotic species being analyzed,G. plecoglossi is likely to represent the earliest offshoot of eukaryotes. Microsporidians might be the extremely ancient eukaryotes which have diverged before an occurrence of mitochondrial symbiosis.
Sequence availability: The nucleotide sequence data reported here appear in the GSDB, DDBJ, EMBL, and NCBI databases with the accession number D32139 相似文献
65.
SFA-1, a novel cellular gene induced by human T-cell leukemia virus type 1, is a member of the transmembrane 4 superfamily. 总被引:5,自引:1,他引:4 下载免费PDF全文
A novel cellular gene termed SFA-1 was isolated by differential hybridization of a cDNA library, using probes obtained from an adult T-cell leukemia cell line in comparison with probes obtained from normal CD4+ T cells and the MOLT-4 cell line. The mRNA of the SFA-1 gene is approximately 1.6 kb in size and encodes a protein of 253 amino acids, containing four putative transmembrane domains, a number of cysteine residues, and one potential N-glycosylation site in a major hydrophilic region between the third and fourth transmembrane domains. Expression of the SFA-1 gene was either absent or present at a low level in lymphoid cells but was up-regulated after transformation by human T-cell leukemia virus type 1 and transactivated by Tax. SFA-1 was broadly expressed in many human cell types and conserved in different species. Computer-aided comparison showed that SFA-1 had significant sequence homology and common structural features with members of the transmembrane 4 superfamily. SFA-1 antigen was detected as a 29-kDa membrane protein by immunoblotting, using anti-SFA-1 monoclonal antibody. 相似文献
66.
67.
Yuri Hasegawa Hirotaka Uosaki Shuji Adachi Ryuichi Matsuno 《Biotechnology letters》1996,18(4):367-372
Summary Stereoselective oxidation of (S)-isomer of rac-1-phenylethanol (1-PA) by the yeast Pachysolen tannophilus IFO 1007 immobilized into calcium-alginate gels was investigated to produce (R)-isomer. Continuous production of (R)-isomer was accomplished for more than 80 h with an enantiomeric excess of > 90% using a bioreactor of a fluidized-bed type. 相似文献
68.
Alterations in cell membrane structure and expression of a membrane-associated protein after adaptation to osmotic stress 总被引:3,自引:0,他引:3
69.
Hiroshi Hasegawa 《Physiologia plantarum》1996,96(2):199-204
Screening for mutants deficient in the high affinity system of nitrate uptake was performed using mutagenized M2 population of rice ( Oryza sativa , cv. Nipponbare or Kinmaze). For selecting mutants, M2 seedlings were transferred individually to 10 ml solution containing 250 μ M potassium nitrate and 500 μ M calcium sulphate at 20 or 28°C. After 6 or 24 h, nitrate concentration of the solution was determined with a nitrate selective electrode and the seedlings showing impaired nitrate uptake were selected as nitrate uptake deficient variants. Of 74 variants, three were confirmed to be mutants with low nitrate uptake ability in the M3 generation. Potassium uptake ability also decreased in the mutants. Three mutants were divided into two groups based on the analysis of nitrate reductase (NR, EC 1.6.6.1) activity and chlorate resistance. Two, NUE13 and NUE36 , had a lower level of NR activity than the original cultivar and were not resistant to chlorate, while the seedlings of NUE50 had the same level of NR activity as the original cultivar and were more resistant to chlorate than the original cultivar. All mutants were resistant to cesium, a toxic ion analogue for potassium, suggesting that the decreased levels of both nitrate and potassium uptake were coupled to the change of plasma membrane H+ -ATPase activity. 相似文献
70.
Maruyama Akiko; Yoshiyama Makoto; Adachi Yasuhiro; Tani Akinobu; Hasegawa Ryo; Esashi Yohji 《Plant & cell physiology》1996,37(8):1054-1058
The effects of allyl, sulfur and cyanogenic compounds on thegermination of upper cocklebur (Xanthium pennsylvanicum Wallr.)seeds were examined. Mercaptoethanol and methylmercaptan aswell as KCN, substrates for rßcyanoalanine synthase(CAS), and H2S and thiocyanate, the products of the CAS catalyzingreaction, were effective in promoting germination, suggestingthe involvement of CAS in germination. Most of allyl compounds, especially allylthiourea, as well asethylene which activated CAS [Hasegawa et al. (1994) Physiol.Plant. 91: 141], promoted the germination in an abnormal typewhich occurred by the predominant growth of cotyledons as didC2H4 [Katoh and Esashi (1975) Plant Cell Physiol. 16: 687].However, they failed to activate CAS unlike ethylene, and toliberate free ethylene during an incubation period. It was thuspossible that an C2H4-like double bond within allyl compoundscan act to promote seed germination. (Received June 10, 1996; Accepted August 21, 1996) 相似文献