| Abstract: | Viruses which infect bacteria are called bacteriophages; the bacteriophage lambda (λ) infects certain strains of the bacterium Escherichia coli K12. Near the right end of the linear DNA of bacteriophage lambda, from the coordinates 0.96 to 1.00, is a region of DNA approximately 2079 base pairs which is previously uncharacterized with respect to function; that is, no identifiable genes have been mapped in this region. In addition, no mutants have ever been isolated which contain either insertions or deletions of the region which spans the coordinates 0.96 to 0.98. A 1576 base pair deletion of this region was constructed on a plasmid using recombinant DNA techniques and recombined back into lysogenic (dormant) phage. Once the deletion was physically characterized, the lysogens were placed under conditions which normally induce bacteriophage lambda development and maturation. The production of mature infectious viral particles was then assayed. It is shown that viable phages carrying the engineered deletion were isolated. Furthermore, the number of phage particles produced did not differ appreciably between deleted and undeleted lysogens. Thus, the introduced deletion did not affect bacteriophage lambda viability, and it is likely that if any genetic elements are contained in this region they are non-essential to lambda growth in the laboratory strain of Escherichia coli used. |
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