Direct and general selection for lysogens of Escherichia coli by phage lambda recombinant clones.

摘要: We report a simple in vivo technique for introducing an antibiotic resistance marker into phage lambda. This could be used direct selection of lysogens harboring recombinant phages from the Kohara lambda bank (a collection ordered clones carrying Escherichia coli DNA segments). The two-step method uses homologous recombination and packaging to replace nonessential lying between lysis genes right cohesive (cos) end with neomycin phosphotransferase (npt) gene Tn903. occurs during lytic growth on plasmid-containing host strain. Neomycin-resistant (npt+) are then selected lysates containing progeny by transduction polA1 lysogenic strain resistance. have tested this two different clones; both cases, cotransduced auxotrophic carried clone, indicating complete genetic linkage. Linkage was verified restriction mapping purified clone. also demonstrate that insertion npt+ prophage can readily distinguished bacterial chromosomal sequences.