Apparent mutagenic effect of induction of lambda prophage inserted between lysA and thyA

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Bacteriophage lambda can integrate into the Escherichia coli genome as a prophage.
• Induction of prophage can lead to cell lysis or other genetic alterations.

Purpose of the Study:

• To investigate the genetic consequences of inducing a heat-inducible lambda prophage in Escherichia coli.
• To characterize auxotrophic mutants arising after prophage induction.

Main Methods:

• Induction of a lambda prophage inserted between lysA and thyA genes in E. coli.
• Isolation and characterization of auxotrophic mutants from surviving cells.
• Mapping of mutant loci using F' episome complementation.

Main Results:

• Induction resulted in auxotrophic mutants not explained by deletions.
• Mutants exhibited spontaneous reversibility.
• Mutant properties were mapped to specific chromosomal locations.

Conclusions:

• Lambda prophage induction in E. coli appears to induce a mutagenic state.
• This mutagenic state leads to the formation of auxotrophic mutants.
• The observed mutations are distinct from deletion events associated with hybrid phage formation.