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Biomedical subjects

R W Davis

Publications and source records attributed to R W Davis.

At least 253 records · Page 14Linked to original sources
PubMed1974

Viable molecular hybrids of bacteriophage lambda and eukaryotic DNA.

A bacteriophage lambda strain has been constructed and a method developed by which DNA from potentially any source can be covalently inserted through EcoRI cohesive ends into the middle of the lambda DNA. These hybrid DNAs can infect nonrestricting Escherichia coli cells and can then propagate as plaque-forming phage. A unique feature of this lambda strain is that extra DNA in the middle of its genome is required for plaque formation. A large number of such phages have been produced with E. coli DNA and Drosophila melanogaster DNA.

Animals↗
PubMed1972

Cleavage of DNA by R 1 restriction endonuclease generates cohesive ends.

R(1) restriction endonuclease cleaves duplex DNA at a specific sequence, probably 6 nucleotide pairs in length, by making two single-strand staggered cleavages, generating 5'-phosphoryl and 3'-hydroxyl termini. The single-strand ends produced at each break have identical and complementary sequences of 4 or 6 nucleotides in length. Therefore, the cleavage site possesses a 2-fold rotational axis of symmetry perpendicular to the helix axis. The ends of full-length linear SV40 DNA, generated by R(1) endonuclease cleavage, can be joined by Escherichia coli ligase to regenerate duplex, fully infectious, covalently-closed circular molecules. It was further found that all R(1) endonuclease-generated ends are identical and complementary. Therefore, any two DNA molecules with R(1) sites can be "recombined" at their restriction sites by the sequential action of R(1) endonuclease and DNA ligase to generate hybrid DNA molecules.

Animals↗
PubMed1972

Disaster drills.

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Disasters↗