Plasmid co-integrates of prophage lambda and R factor R100

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Bacteriophages, such as prophage lambda, are viruses that infect bacteria.
• Plasmids like R100 carry antibiotic resistance genes and can be transferred between bacteria.
• Understanding the integration and organization of genetic elements is crucial for bacterial genetics.

Purpose of the Study:

• To isolate and characterize single and tandem insertions of prophage lambda into the R100 plasmid.
• To determine the precise sequence and organization of antibiotic resistance genes on the R100 plasmid.
• To generate high-frequency transducing phages for genetic analysis.

Main Methods:

• Isolation of single and tandem prophage lambda insertions into R100.
• Characterization of insertion sites, including transfer genes and the finO gene.
• Isolation of deletion mutants to establish gene order.
• Preparation of high-frequency transducing phage lysates.

Main Results:

• Successfully isolated various prophage lambda insertions in R100.
• Identified insertions in transfer genes, the finO gene, and other regions.
• Established the antibiotic resistance gene sequence on R100 as tet-cml-fus-str-sul-mer.
• Generated high-frequency transducing phages (lambdamer, lambdasul str, lambdasul str cml).

Conclusions:

• The sequence of antibiotic resistance genes on R100 has been definitively established.
• The generated high-frequency transducing phages are valuable tools for future genetic studies of R100.
• Prophage lambda can be used as a mobile genetic element to probe and manipulate the R100 plasmid.