[Site-specific recombination between phages lambda and phi 81 and integration of hybrid phages lambda-phi 81]

Area of Science:

• Molecular Biology
• Genetics
• Microbiology

Background:

• Bacteriophages lambda and phi81 are model systems for studying genetic recombination.
• The int-function is crucial for site-specific integration of phage DNA into host genomes.
• Hybrid phages can arise from recombination events between different phage types.

Purpose of the Study:

• To investigate the dependence of hybrid phage formation frequency on the int-function of both lambda and phi81 phages.
• To characterize hybrid phages resulting from recombination between lambda and phi81.
• To determine the integration efficiency of these hybrid phages into the bacterial chromosome.

Main Methods:

• Studying the int-function of lambda and phi81 phages.
• Inducing recombination between lambda and phi81.
• Isolating phages with hybrid att-sites (Plambda OP'phi81 and Pphi81OP'lambda).
• Measuring the efficiency of phage integration into the bacterial chromosome.

Main Results:

• The frequency of immlambdahphi81 and immphi81hlambda hybrid phage formation is dependent on the int-function of both parental phages.
• Phages with hybrid att-sites, specifically Plambda OP'phi81 and Pphi81OP'lambda, were successfully isolated.
• The integration efficiency of these isolated hybrid phages into the bacterial chromosome was determined.

Conclusions:

• The int-function of both lambda and phi81 phages plays a significant role in the formation of their respective hybrid phages.
• Hybrid att-sites can be generated through recombination, leading to novel phage structures.
• Understanding these mechanisms is vital for phage biology and genetic engineering applications.