Physical mapping of bacteriophage lambda DNA with restriction endonuclease HpaI

Area of Science:

• Molecular Biology
• Genomics
• Enzymology

Background:

• Restriction endonucleases are crucial tools for DNA manipulation and analysis.
• Lambda phage DNA is a well-characterized model system for genetic studies.
• Understanding DNA fragment sizes and order is fundamental for genome mapping.

Purpose of the Study:

• To characterize the cleavage pattern of the Haemophilus parainfluenzae restriction endonuclease (HpaI) on lambda phage DNA.
• To construct a physical map of the lambda phage genome using HpaI restriction fragments.
• To investigate the utility of HpaI in analyzing specific regions of the phage genome, particularly the left arm.

Main Methods:

• Cleavage of lambda phage DNA using the HpaI restriction endonuclease.
• Determination of fragment sizes using gel electrophoresis.
• Ordering of fragments through analysis of deletion/substitution mutants, double digests with BamHI, and partial site protection with distamycin A and actinomycin D.

Main Results:

• HpaI digestion of lambda phage DNA yielded 14 distinct fragments.
• A physical map of the lambda phage genome was successfully constructed based on these fragments.
• Specific fragments originating from the left arm of the lambda genome were identified.

Conclusions:

• The restriction enzyme HpaI effectively fragments lambda phage DNA, facilitating detailed physical mapping.
• The generated physical map provides a framework for further investigation of the lambda phage genome.
• HpaI analysis offers a valuable approach for studying the structure and function of the lambda phage left arm.