Cloning and expression vectors are essential tools in molecular biology that
enable researchers to manipulate and study genes and proteins. Cloning vectors are
DNA molecules that can carry foreign DNA fragments and introduce them into host
cells. Expression vectors are specialized cloning vectors designed to drive the
expression of foreign genes in a host cell, allowing researchers to produce large
quantities of recombinant proteins. The most commonly used cloning vectors are
plasmids; circular DNA molecules that can replicate independently of the host
chromosome. Plasmids can be engineered to contain various features such as selectable
markers, multiple cloning sites, and regulatory sequences. These features make
plasmids versatile application tools, including gene cloning, mutagenesis, and genetic
engineering. Expression vectors are typically based on plasmids and contain additional
elements that enable the efficient expression of the foreign gene. These elements
include a strong promoter, a ribosome binding site, and a transcription terminator,
which work together to ensure the production of the recombinant protein. The choice of
expression vector depends on the desired protein expression level, the host cell type,
and downstream applications. The use of cloning and expression vectors has
revolutionized the field of molecular biology, enabling the production of recombinant
proteins, genetic engineering of organisms, and gene therapy. However, using these
tools requires careful consideration of potential risks, such as unintended genetic
modifications or the spread of genetically modified organisms.
Keywords: Complementary DNA, Expression vector, Molecular cloning, Oligonucleotide sequence, Restriction enzyme.
