Open AccessBacteriophage λ Having Eco RI Endonuclease Sites Only in the Nonessential Region of the Genome
Author(s) -
Alain Rambach,
Pierre Tiollais
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.10.3927
Subject(s) - bacteriophage , genome , endonuclease , biology , genetics , dna , computational biology , gene , escherichia coli
A derivative of λb221 that has lost by mutation allEco RI restriction sites has been isolated by alternative growth on restrictive and nonrestrictive strains. It has an efficiency of plating equal to 1 on the restrictive strain. Genetic cross of this bacteriophage with λplac5 imm21 gave rise to recombinants of intermediate restricting ratios. The analysis of theEco RI endonuclease-cleaved DNA by polyacrylamide gel electrophoresis, compared with the genetic results, has permitted identification ofEco RI endonuclease cleavage sites in the recombinants. The genotypes are: λplac5 CI857 sRI λ3 0 sRI λ2 0 sRI λ1 0 and λplac5 CI857 sRI λ2 0 sRI λ1 0 . The remaining cleavage sites, respectively,sRIlac sRI λ4 andsRIlac sRI λ4 sRI λ3 , are all located in a region nonessential for bacteriophage multiplication. The involvement of these mutant bacteriophages as vector for foreign genes are discussed.