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K. Hosaka G. A. de Zoeten R. E. Hanneman Jr. 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,75(5):741-745
Summary The chloroplast DNA (ctDNA) of Solanum tuberosum ssp. tuberosum (T type) and S. chacoense (W type) yield five different restriction fragment patterns with five different restriction endonucleases. DNA-DNA hybridization tests revealed that these differences were all caused by one physical deletion (about 400 bp in size) in the ctDNA of ssp. tuberosum. This suggests that T type ctDNA of the common potato and of Chilean tuberosum originated from W type ctDNA. The deleted region of the T type ctDNA is probably not concerned with gene-cytoplasmic male sterility.Reference to a specific brand or firm name does not constitute endorsement by the U.S. Department of Agriculture over others of a similar nature not mentioned 相似文献
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A convenient approach to the synthesis of medium size oligodeoxyribonucleotides by improved new phosphite method. 下载免费PDF全文
Improvement of the new phosphite method for the synthesis of oligodeoxyribonucleotides using the deoxyribonucleoside 3'-bis(1,1,1,3,3,3- hexafluoro-2-propyl) phosphite unit has been carried out via the hydrolysis and capping steps, without any side reaction products. The new phosphite unit and capping agent, bis(1,1,1,3,3,3-hexafluoro-2-propyl)-2-propyl phosphite, is readily activated by N-methylimdazole under very mild condition on a solid support. This operation involves a one pot reaction, which is an advantage over both the phosphite and H- phosphonate approaches. The mechanism of internucleotidic bond formation of the new phosphite method is also discussed. 相似文献
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Who is the mother of the potato? — restriction endonuclease analysis of chloroplast DNA of cultivated potatoes 总被引:1,自引:0,他引:1
K. Hosaka 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(5):606-618
Summary Chloroplast DNA from 44 lines of 16 wild and 7 cultivatedSolanum species were compared by restriction endonuclease analysis. Seven chloroplast genome types were identified among them by 5 restriction enzymes: Type A (S. tuberosum ssp.andigena andS. maglia); Type S (S. goniocalyx, S. phureja, S. stenotomum, S. ×chaucha and a line of ssp.andigena); Type C (S. acaule, S. bukasovii, S. canasense, S. multidissectum andS. ×juzepczukii); Type T (S. tuberosum ssp.tuberosum); Type W (other wild species); Type W (S. chacoense f.gibberulosum) and Type W (S. tarijense). From this cytoplasmic identification, it was concluded thatS. goniocalyx, S. phureja, S. ×chaucha and ssp.andigena were derived fromS. stenotomum or its primitive type, which may have originally evolved itself fromS. canasense. The chloroplast genome of the European potato, however, was introduced from the Chilean potato, which might have been primarily constructed with the nuclear genome from ssp.andigena and with cytoplasm from other species. The cytoplasmic donor of the Chilean potato could not be determined.Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Japan, No. 479. This work was done at Kyoto University when the author was a graduate student at Kobe University 相似文献
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Interconversion of polyamines in wild-type strains and mutants of yeasts and the effects of polyamines on their growth 总被引:1,自引:0,他引:1
Koei Hamana Shigeru Matsuzaki Kohei Hosaka Satoshi Yamashita 《FEMS microbiology letters》1989,61(1-2):231-236
Yeasts of wild-type strains, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Candida albicans were shown to have the ability to form aminopropylcadaverine and aminopropylhomospermidine from cadaverine and homospermidine, respectively. A polyamine autotroph S. cerevisiae 179-5, which lacks ornithine decarboxylase, produced both aminopropylcadaverine and aminopropylhomospermidine, while another mutant S. cerevisiae Y 260 A, which lacks spermine synthase, formed only aminopropylcadaverine. Naturally-occurring triamines and tetraamines except norspermidine and norspermine stimulated the growth of S. cerevisiae 179-5. All the six aliphatic diamines with carbon chain length ranging from one to six were effective in activating the growth of S. cerevisiae 179-5, though all of them were not converted to either triamines or tetraamines. 相似文献
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Biosynthesis of lipopolysaccharide in Escherichia coli. Cytoplasmic enzymes that attach 3-deoxy-D-manno-octulosonic acid to lipid A 总被引:8,自引:0,他引:8
K A Brozek K Hosaka A D Robertson C R Raetz 《The Journal of biological chemistry》1989,264(12):6956-6966
Previous studies in our laboratory led to the elucidation of the covalent structure of a tetraacyldisaccharide 1,4'-bisphosphate precursor of lipid A (designated lipid IVA), that accumulates at 42 degrees C in temperature-sensitive mutants defective in 3-deoxy-D-manno-octulosonic acid (KDO) biosynthesis (Raetz, C. R. H., Purcell, S., Meyer, M. V., Qureshi, N., and Takayama, K. (1985) J. Biol. Chem. 260, 16080-16088). Using [4'-32P]lipid IVA as the probe, we now demonstrate the existence of cytoplasmic KDO-transferases in Escherichia coli capable of attaching 2 KDO residues, derived from CMP-KDO, to lipid IVA. A partial purification has been developed to obtain a cytoplasmic subfraction that adds these 2 KDO residues with a 90% yield. The product is shown to have the stoichiometry of (KDO)2-IVA by fast atom bombardment mass spectrometry and NMR spectroscopy. The partially purified enzyme can utilize alternative lipid-disaccharide cosubstrates bearing five or six fatty acyl chains, but it has an absolute requirement for a monophosphate residue at position 4' of the lipid acceptor. When reincubated with a crude cytoplasmic fraction, a nucleoside triphosphate and Mg2+, (KDO)2-IVA is rapidly metabolized to more polar substances, the identity of which is unknown. The KDO-transferase(s) described in the present study should be very useful for the semisynthetic preparation of complex lipopolysaccharide substructures and analogs. 相似文献
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Although in vitro studies have shown that oxygen free radicals depress the sarcolemmal Ca2+-pump activity and thereby may cause the occurrence of intracellular Ca2+ overload for the genesis of contractile failure, the exact relationship between changes in sarcolemmal Ca2+-pump activity and cardiac function due to these radicals is not clear. In this study we examined the effects of oxygen radicals on sarcolemmal Ca2+ uptake and Ca2+-stimulated ATPase activities as well as contractile force development by employing isolated rat heart preparations. When hearts were perfused with medium containing xanthine plus xanthine oxidase, the sarcolemmal Ca2+-stimulated ATPase activity and ATP-dependent Ca2+ accumulation were depressed within 1 min whereas the developed contractile force, rate of contraction and rate of relaxation were increased at 1 min and decreased over 3–20 min of perfusion. The resting tension started increasing at 2 min of perfusion with xanthine plus xanthine oxidase. Catalase showed protective effects against these alterations in heart function and sarcolemmal Ca2+-pump activities upon perfusion with xanthine plus xanthine oxidase whereas superoxide dismutase did not exert such effects. The combination of catalase and superoxide dismutase did not produce greater effects in comparison to catalase alone. These results are consistent with the view that the depression of heart sarcolemmal Ca2+ pump activities may result in myocardial dysfunction due to the formation of hydrogen peroxide and/or hydroxyl radicals upon perfusing the hearts with xanthine plus xanthine oxidase. 相似文献