Question

Identify the vector which is not a phage vector among the following?

• A. pBR322
• B. MP13MP2
• C. \(\lambda\)gt 10
• D. \(\lambda\)ZAPII

Hint:

• Plasmid vectors Circular DNA, common for routine cloning (e.g., pBR322, pUC series).
• Bacteriophage vectors Derived from viruses infecting bacteria.
  • Lambda (\(\lambda\)) phage vectors For larger inserts, genomic/cDNA libraries.
  • M13 phage vectors For single-stranded DNA production.
• Cosmids Hybrid of plasmid and lambda phage features, for large inserts.
• Artificial Chromosomes (BACs, YACs) For very large DNA fragments.

Answer 1

The Correct Option is A

Vectors are DNA molecules used as vehicles to carry foreign genetic material into another cell, where it can be replicated and/or expressed.

• Phage Vectors (Bacteriophage Vectors): These are cloning vectors derived from bacteriophages (viruses that infect bacteria). They are used for cloning larger DNA fragments than plasmids can typically accommodate. Examples:
  • Lambda (\(\lambda\)) phage vectors: Such as \(\lambda\)gt10, \(\lambda\)gt11, \(\lambda\)ZAPII, EMBL vectors. Used for constructing genomic libraries and cDNA libraries. (Options c and d are lambda phage vectors).
  • M13 phage vectors: Filamentous phages that infect E. coli. Used for obtaining single-stranded DNA (useful for sequencing and site-directed mutagenesis). Examples include M13mp series like M13mp18, M13mp19. (Option b, "MP13MP2", is likely a typo for an M13 derivative).
• Plasmid Vectors: Small, circular, extrachromosomal DNA molecules found naturally in bacteria. They are widely used for cloning smaller DNA fragments (typically up to ~10-15 kb). Example: pBR322 (Option a) is one of the earliest and classic E. coli plasmid cloning vectors. It contains an origin of replication, selectable markers (e.g., antibiotic resistance genes like amp\(^R\), tet\(^R\)), and multiple cloning sites.
• Other vectors include Cosmids, BACs (Bacterial Artificial Chromosomes), YACs (Yeast Artificial Chromosomes), etc.

The question asks to identify the vector which is NOT a phage vector. pBR322 is a plasmid vector. MP13MP2 (likely M13mp series) is an M13 phage vector. \(\lambda\)gt10 and \(\lambda\)ZAPII are lambda phage vectors. Therefore, pBR322 is not a phage vector. \[ \boxed{\text{pBR322}} \]