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51.
Identification of Tn4430, a transposon of Bacillus thuringiensis functional in Escherichia coli 总被引:3,自引:0,他引:3
Didier Lereclus Jacques Mahillon Ghislaine Menou Marguerite-M. Lecadet 《Molecular & general genetics : MGG》1986,204(1):52-57
Summary The mobile genetic element Tn4430, originating from the gram-positive bacterium, Bacillus thuringiensis, and previously described as the Th-sequence, is the first transposon isolated from the genus Bacillus. In the present work a gene (APH-III) conferring resistance to kanamycin was inserted into this 4.2 kb transposon. Transposition experiments showed that Tn4430APH-III could transpose in the gram-negative host Escherichia coli when its insertion functions were supplied by an intact copy of Tn4430. By transposing Tn4430APH-III directly onto pBR322, it was possible to determine the nucleotide sequence of the terminal inverted repeats of Tn4430 and of the target DNA site. Identical 38 bp in inverted orientation are situated at each end of the transposon and there is a direct duplication of 5 bp at the insertion site. Thus, it is clear that Tn4430 is closely related to the transposons belonging to the Tn3 family (class II elements). 相似文献
52.
Summary Inoculation of carrot discs and Lotus corniculatus plantlets with mixtures of different Agrobacterium rhizogenes or of A. rhizogenes and A. tumefaciens or with Agrobacterium strains harboring both an Ri and a modified Ti plasmid resulted in frequent multiple (pluribacterial) transformation of cells, as revealed by the mixed opine-type of hairy roots arising from them. Multiple transformation may account for the presence of dispersed T-DNA inserts in crown gall and hairy root lines. A plant genetic engineering strategy based on segregation of T-DNA inserts in the progeny of multiple transformants is proposed. 相似文献
53.
54.
N Bonnet C Quintana P Favard N Favard 《Biology of the cell / under the auspices of the European Cell Biology Organization》1985,55(1-2):125-138
A microcomputer reconstruction technique has been developed in order to permit a larger exploitation of stereomicroscopy. The microcomputer facility consists of a digitizing tablet, a microcomputer, a graphics terminal, a graphics plotter and a printer. The technique has been applied to the study of HVEM stereopairs, performed by recording two images of the same area of a specimen (thick section of araldite-embedded leech ganglion neurons), tilted relative to the beam axis through an angle 0/20 degrees. Coordinates of N conjugate points of interest, expressed in a common reference system were obtained with the help of a digitizing tablet and the misorientation between the two images was determined by a method based on a least square technique. New projections of the object on different planes are provided by the microcomputer facility. Also the microcomputer method permits to obtain new stereopairs drawings, in various orientations and slices from a three-dimensional reconstruction of the object oriented in any direction in space. The method permits to obtain computed anaglyph drawings, printed here, which are stereoviews of the same object. 相似文献
55.
A yeast genomic library in Escherichia coli, constructed by insertion of Sau3A restriction fragments into the hybrid Saccharomyces cerevisiae-E. coli plasmid pFL1, was screened by a radioimmunoassay (RIA) for colonies expressing yeast aspartyl-tRNA synthetase (AspRS). Four clones were isolated by this technique. Data obtained by Southern and restriction analysis of the inserts showed a common 3.8-kb BamHI restriction fragment which, when inserted into the plasmid pFLl, gave a positive RIA. Several controls showed that this 3.8-kb insert codes for the entire AspRS : (i) S. cerevisiae transformed by the PFL1 plasmid carrying the 3.8-kb fragment overproduces AspRS activity by a factor of ten compared to the wild-type yeast strain; and (ii) a new protein with electrophoretic behaviour similar to AspRS and immuno-reactive toward anti-AspRS appears in crude extracts of transformed yeast and E. coli. 相似文献
56.
Mariann Thymann Bernadette Hoste Wolfgang Scheffrahn Jacques Constans Hartwig Cleve 《Human genetics》1985,69(3):224-227
Summary The proteins of three anodal Gc1 variants, Gc 1A16, 1A11, and 1A17, are characterized by the most acidic isoelectric points observed so far among the different Gc mutants. Stepwise removal of N-acetylneuraminic acid (NANA) by treatment with neuraminidase was performed to estimate the degree of sialilation of these Gc variants. The results indicate that both proteins, the anodal and the cathodal component of these Gc 1 mutants, carry sialic acid residues. This observation is remarkable in so far as usually only the anodal component of the Gc 1 protein contains NANA and only a single residue. From the experiments carried out it can be deduced that Gc 1A16 has two NANA residues in the anodal and one NANA residue in the cathodal component. Gc 1A16 was found in four members of three generations in a Danish family; the variant segregated as a Mendelian trait. More difficult to interprete are the results obtained with the variants Gc 1A11 and Gc 1A17. Gc 1A11 probably has three NANA residues in the anodal and two NANA residues in the cathodal component. Gc 1A11 has been observed in two mother-child pairs and is presumably also a simple genetic trait. Gc 1A17 has also several NANA residues in both Gc proteins; it is suggested that the anodal component has either three or four NANA residues and the cathodal component either two or three NANA residues. Family information on this variant is not yet available. 相似文献
57.
Bonnet JA Koellmann CJ Dekkers-de Kok HE Roels JA 《Biotechnology and bioengineering》1984,26(3):269-274
Saccharomyces cerevisiae CBS 426 was grown in continuous culture in a defined medium with a mixture of glucose and succinic acid as the carbon source. Growth on succinic acid was possible after long adaptation periods. The flows of glucose, succinic acid, oxygen, carbon dioxide, and biomass to and from the system were measured. It proved necessary to expand our previous model to accommodate the active transport of succinic acid by the cell. The values found for the efficiency of the oxidative phosphorylation (P/O) and the amount of ATP needed for production of biomass from monomers gave the same values as found for substrate mixtures taken up passively. 相似文献
58.
In order to study their natural killer effect, guinea pig splenic Kurloff cells were fractionated by Percoll discontinuous density gradient centrifugation. Kurloff cells were collected and tested for cytotoxicity in a 24-hr chromium-release test. Comparison of different splenic cellular samples (of males or estrogenized females) with increasing percentage of Kurloff cells, revealed a highly significant positive correlation (r = 0.93, α < 0.01) with the cellular cytotoxicity developed against the K 562 target cells. 相似文献
59.
Géraldine Bonnard François Michel Jacques Henry Weil André Steinmetz 《Molecular & general genetics : MGG》1984,194(1-2):330-336
Summary The gene encoding the tRNA
UAA
Leu
from broad bean chloroplasts has been located on a 5.1 kbp long BamHI fragment by analysis of the DNA sequence of an XbaI subfragment. This gene is 536 bp long and is split in the anticodon region. The 451 bp long intron shows high sequence homology over about 100 bp from each end with the corresponding regions of the maize chloroplast tRNA
UAA
Leu
intron. These conserved sequences are probably involved in the splicing reaction, for they can be folded into a secondary structure which is very similar to the postulated structure of the intron from the autosplicable ribosomal RNA precursor of Tetrahymena. Very little sequence conservation is found in the 5-and 3-flanking regions of the broad bean and maize chloroplast tRNA
UAA
Leu
genes. 相似文献
60.
Phenolamides and floral induction of Cichorium intybus in different conditions of culture in glass-room or in vitro. Three complexes between phenols and amines (phenolamides) have been found in Cichorium intybus L., a plant with an absolute requirement of vernalisation followed by long days for flowering. Upon hydrolysis, these complexes (A, B and C) liberate aromatic amines whose exact identification is in progress, but which are closely related to dopamine, tyramine and serotonin, respectively. In a first series of experiments, phenolamides were studied in the buds of plants grown in the greenhouse under varying conditions. Only buds from plants which flower in long days contained large amounts of these compounds. Much smaller amounts were found in buds at the end of vernalisation (at 2–4°C) before long-day treatment as well as in buds kept in the vegetative state after vernalisation by being grown in short days (8 h light) or in total darkness. In a second series of experiments, phenolamides were studied in bud-forming calli induced in vitro on explants of tuberised root. After sixteen days of culture in continuous light, large quantities of phenolamide were found in the buds and calli of the upper part of the explant, while the lower part which never produces buds contained much less. Buds formed under continuous light produce inflorescences in approximately one month. Various other culture conditions make it possible to maintain the explants in the vegetative state. This can be obtained by short-day conditions, or otherwise under continuous illumination by decreasing the sugar or increasing the NAA levels in the medium. After 13 days of culture, the phenolamide levels were much lower under all of these conditions, than under conditions favourable to floral induction. Compound C is absent or present in trace amounts in vegetative buds. The significance of the differences observed between floral and vegetative buds is supported by the sensitivity of the analytical techniques used. The accumulation of phenolamides in tissues of Cichorium intybus appears to be closely linked to floral induction. Under continuous light it begins very early in young buds and even in the calli that bear these buds. 相似文献