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What is a plasmid vector and what is its significance?

What is a plasmid vector and what is its significance?

Plasmid vectors are the vehicles used to drive recombinant DNA into a host cell and are a key component of molecular cloning; the procedure of constructing DNA molecules and introducing it into a host cell.

Why are plasmids called vectors?

Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. Scientists have taken advantage of plasmids to use them as tools to clone, transfer, and manipulate genes. Plasmids that are used experimentally for these purposes are called vectors.

What is the example of plasmid vector?

Phagemid vectors are plasmids having a small segment of a filamentous phage M-13, fd, or F1 phage capable to carry up to 10 kb passenger DNA. Examples: pEMBL series of plasmids pBluescript family plasmids.

What does plasmid cloning vector mean?

A cloning vector is a small piece of DNA that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes. The cloning vector may be DNA taken from a virus, the cell of a higher organism, or it may be the plasmid of a bacterium.

What should a plasmid vector contain?

Most plasmid vectors contain little more than the essential nucleotide sequences required for their use in DNA cloning: a replication origin, a drug-resistance gene, and a region in which exogenous DNA fragments can be inserted (Figure 7-1).

What is the role of cloning vector?

In general, cloning vectors are plasmids that are used primarily to propagate DNA. They replicate in E. coli to high copy numbers and contain a multiple cloning site (also called a polylinker) with restriction sites used for inserting a DNA fragment. An expression vector is a specialized type of cloning vector.

How is foreign DNA is inserted into a plasmid vector?

Foreign DNA is inserted into a plasmid (or any cloning vector) by ligating the DNA into a complementary site in the plasmid. These sites are generated by digesting the DNA and vector with the same restriction enzyme. The foreign DNA is then inserted into the plasmid by the action of the enzyme DNA ligase.

Which is phagemid vector?

A phagemid or phasmid is a DNA-based cloning vector, which has both bacteriophage and plasmid properties. These vectors carry, in addition to the origin of plasmid replication, an origin of replication derived from bacteriophage.

Why are plasmid used as vectors vectors?

Plasmid Vectors: Plasmids are the extra chromosomal genetic elements commonly found in bacteria and are mostly made of double-stranded circular DNA. They are used as vectors in gene cloning , because they have a replication origin in their DNA making them competent of autonomous replication, and also because they generally have one or two restriction sites for several restriction enzymes.

Is a plasmid a cloning vector?

Plasmids are good cloning vectors because they are self replicating, generally small so easy to work with and transform into their host, usually with antibiotic resistance gene(s) to enable selection for transformed hosts, and these days, engineered to have all kinds of useful cloning sites, expression signals and the like.

Are plasmid vectors helpful?

Significance of plasmids dramatically increased with the advent of recombinant DNA technology as they became the first cloning vectors, and even today they are the most widely used cloning vectors especially in gene cloning in bacteria. They enjoy this status because they have very useful properties as cloning vectors that include:

Why are plasmids important?

Plasmids are useful in cloning short segments of DNA. Also, plasmids can be used to replicate proteins, such as the protein that codes for insulin, in large amounts. Additionally, plasmids are being investigated as a way to transfer genes into human cells as part of gene therapy.