A new lambda RES vector with a built-in Tn1721-encoded excision system

Area of Science:

• Molecular Biology
• Genomics
• Recombinant DNA Technology

Background:

• Construction of genomic libraries is crucial for understanding genome organization and function.
• Lambda replacement vectors facilitate cloning large DNA fragments but often require complex manipulation for downstream applications.
• Efficient methods for transferring cloned inserts from lambda vectors to plasmids are needed.

Purpose of the Study:

• To develop a versatile lambda replacement vector system for seamless transfer of cloned genomic fragments into plasmids.
• To enable site-specific excision and conversion of lambda clones into autonomously replicating plasmids.
• To facilitate the construction and manipulation of genomic libraries.

Main Methods:

• Development of the lambda RES vector, derived from lambda EMBL4, incorporating Tn1721 recombination sites.
• Inclusion of a plasmid replication origin (Rtsl) and a kanamycin-resistance (KmR) marker.
• Utilizing Escherichia coli strains harboring Tn1739tnpR for efficient excision and conversion.

Main Results:

• The lambda RES vector allows insertion of 8-14 kb DNA fragments via BamHI or SalI sites.
• Efficient site-specific recombination and conversion of lambda phage particles into kanamycin-resistant colonies were achieved.
• The system demonstrated successful transfer of cloned fragments into autonomously replicating plasmids.

Conclusions:

• The lambda RES vector system provides an efficient method for constructing genomic libraries and transferring inserts to plasmids.
• This vector facilitates downstream applications requiring plasmid-based manipulation of cloned genomic DNA.
• Lambda RES offers a valuable tool for molecular cloning and genetic engineering.