Abstract
Lysogens obtained by infecting Streptomyces albus G with a φC31-pBR322 chimaeric prophage or its δW 12 deletion derivative had increased tetracycline resistance. The ability of the ΔW 12 derivative to transduce tetracycline resistance was inactivated by inserting a viomycin resistance determinant ( vph) into the BamHI site of the pBR322 tet gene, and restored by excising the vph gene. Another deletion mutant (δW 17) of the chimaera, carrying an intact tet gene, was normally unable to transduce tetracycline resistance. This inability was correlated with the finding, by Southern hybridisation analysis, that the att site required for insertion of φC31 prophage into the host chromosome was located within the AW17 deletion. Use of a φC31 lysogenic recipient permitted the integration of the att-deleted phage, presumably by homologous recombination, giving tetracycline-resistant double lysogens. This technique was extended to S. coelicolor A3(2) in the detection of derivatives of the att-deleted phage into which a thiostrepton-resistance determinant ( tsr) had been inserted in vitro. Phage released from double lysogens were mainly recombinants. One such recombinant is a PstI vector for DNA cloning, able to accommodate up to 6 kb of introduced DNA.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.