Vector (molecular biology)

Vector (molecular biology)

Diagram of the pBR322 plasmid, a commonly used vector in molecular biology.

A vector in molecular biology is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated and/or expressed. Vectors are essential tools in genetic engineering and biotechnology.

Types of Vectors

Vectors can be classified into several types based on their function and the type of genetic material they carry:

• Plasmids: Circular DNA molecules that replicate independently of the chromosomal DNA. They are commonly used in cloning and gene expression studies.
• Viral vectors: Modified viruses that can deliver genetic material into cells. They are often used in gene therapy and vaccine development.
• Cosmids: Hybrid vectors that combine features of plasmids and bacteriophages, capable of carrying larger DNA fragments.
• Artificial chromosomes: Large vectors that can carry very large DNA fragments, used in genome mapping and sequencing projects.

Features of Vectors

Vectors typically contain several key features that facilitate their use in genetic engineering:

• Origin of replication (ori): A sequence that allows the vector to replicate within a host cell.
• Selectable marker genes: Genes that confer resistance to antibiotics, allowing for the selection of cells that have taken up the vector.
• Multiple cloning site (MCS): A region containing several restriction enzyme sites that allow for the insertion of foreign DNA.
• Promoter sequences: Regions that initiate transcription of the inserted gene, necessary for gene expression studies.

Applications

Vectors are used in a wide range of applications in molecular biology and biotechnology:

• Gene cloning: Vectors are used to clone genes by inserting them into host cells where they can be replicated.
• Protein expression: Vectors can be used to express proteins in host cells, facilitating the study of protein function and structure.
• Gene therapy: Vectors are used to deliver therapeutic genes into patients' cells to treat genetic disorders.
• Vaccine development: Viral vectors are used to develop vaccines by delivering antigens that stimulate an immune response.

Related pages

• Genetic engineering
• Recombinant DNA
• Gene therapy
• Biotechnology

References

• Sambrook, J., & Russell, D. W. (2001). Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory Press.
• Brown, T. A. (2010). Gene Cloning and DNA Analysis: An Introduction. Wiley-Blackwell.