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M Bastin

Publications and source records attributed to M Bastin.

46 records · Page 3Linked to original sources
PubMed1981

Molecular cloning in plasmid pBR322 giving altered expression of the tetracycline resistance gene.

The two HindIII fragments of polyoma virus DNA were cloned in the HindIII site of plasmid pBR322, a site located in the RNA polymerase promoter involved in the expression of tetracycline resistance. Although insertion of foreign DNA into this site did not always result in the complete loss of tetracycline resistance, Escherichia coli K12 strain chi 1776 harbouring recombinant plasmids exhibited reduced growth properties in liquid culture with tetracycline and could easily be differentiated from bacteria transformed by non-recombinant plasmids. The formation of plasmid multimers increased the resistance to tetracycline at the level of the induction period, presumably as a result of a gene dosage effect.

Cloning, Molecular↗
PubMed1981

Transformation of rat fibroblasts by cloned defective polyoma DNA.

Defective polyoma DNA molecules isolated from mouse cells infected with high-multiplicity-passaged virus were cloned in pBR322, and the recombinant plasmids were tested for their capacity to transform Fischer rat 3T3 cells in culture. Recombinants carrying an intact proximal portion of the early region, i.e., the region coding for both small and middle T antigens, were able to induce the transformed phenotype. A recombinant plasmid containing a defective polyoma genome with a deletion of about 300 base pairs in the region coding for the C-terminal segment of middle T antigen failed to transform.

Animals↗
PubMed1980

Biological properties of polyoma DNA fragments cloned in plasmid pBR322.

The two HindIII fragments of polyoma virus DNA were cloned in the HindIII site of plasmid pBR322, and the biological activity of the recombinant plasmids was tested in tissue culture cells. A mixture of recombinant plasmids containing the HindIII-A and HindIII-B fragments was infectious, but only after cleavage with HindIII. Recombinant plasmids containing the HindIII-A fragment, but not those containing the HindIII-B fragment, induced the transformation of Fischer rat 3T3 cells. These findings indicate that about half of the early region of polyoma virus DNA is not essential for the initiation of the maintenance of transformation.

Animals↗
PubMed1976

Interaction of elongation factor 1 with aminoacylated brome mosaic virus and tRNA's.

Tyrosylated Brome mosaic virus RNA was found to interact with a binary complex of wheat germ, elongation factor 1 and [3H]GTP. Increasing amounts of the aminoacylated viral RNA proportionately reduced radioactivity bound to a nitrocellulose filter, as has previously been noted by others for the charged forms of tobacco mosaic virus, turnip yellow mosaic virus, and tRNA's. However, Sephadex chromatography of the products showed that instead of forming the ternary complex elongation factor-GTP-aminoacyl RNA, the viral RNA caused release of GTP from its complex with elongation factor. Acetylated tyrosyl Brome mosaic virus RNA did not react with the binary complex,and only a slight degree, if any, of stabilization of tyrosine bound to viral RNA was observed after interaction with elongation factor 1. Although such interactions are similar to the reaction of elongation factor with aminoacyl-tRNA , the release of GTP is different and accentuates the possible role for aminoacylation in transcription rather than in translation events.

Guanosine Triphosphate↗
PubMed1975

Radioactive labelling of borme mosaic virus.

Brome mosaic virus (BMV) can be radioactively labelled by allowing virus synthesis to take place in barley leaves whose cut ends are placed in solutions of radio active precursors of BMV. When barley plants are infected by inoculation of the first emerging leaf, the rate of incorporation of both [14C]-leucine and [32P]-ortho-phosphate into virus particles was found to be maximal in the second leaf, cut and labelled 4 to 5 days after inoculation. The rate of incorporation declined when the labelling or the cutting and labelling were delayed, even though assembly of particles still took place from pre-formed components. An exposure of 72 h to an appropriate amount of 32P yielded highly radioactive BMV RNA for possible sequencing studies. A specific radioactivity (32P) of the order of 1 mCi/mg RNA can be obtained readily.

Adenosine↗