The main difference between cloning vector and plasmid vector is that a cloning vector is a DNA molecule that is used to carry foreign DNA fragments into a host cell where they are replicated, whereas a plasmid vector is a specific type of cloning vector that is derived from a plasmid and can replicate independently from the chromosomal DNA.
Cloning vectors and plasmid vectors are two important tools in molecular biology to clone and manipulate DNA sequences. Although both vectors help to carry foreign DNA fragments into host cells, they differ in size, structure, and function.
Key Areas Covered
1. What is a Cloning Vector
– Definition, Features, Use
2. What is a Plasmid Vector
– Definition, Features, Use
3. Difference Between Cloning Vector and Plasmid Vector
– Comparison of Key Differences
Key Terms
Cloning Vector, Plasmid Vector
What is a Cloning Vector
A cloning vector is a DNA molecule that carries foreign DNA into the host cell. Cloning vectors can self-replicate. These vectors have a specific set of features, including multiple cloning sites, selectable markers, and the origin of replication (ORI) that facilitate the insertion and propagation of foreign DNA in a host cell. Moreover, there are various sources for cloning vectors. Some of them are bacteriophages, bacterial chromosomes, and plasmids. Artificial chromosomes are another type of cloning vector that is larger and more complex than plasmids and can carry even larger DNA fragments.
Generally, researchers choose cloning vectors according to the specific application and the size of the DNA fragment they need to clone. For example, a viral vector like adenovirus or retrovirus is useful in expressing a protein in a mammalian cell. This is because these vectors are capable of expressing and infecting genes in mammalian cells. If the need is to create a transgenic organism with a specific trait, an artificial chromosome vector can be used. This is because these vectors can carry larger DNA fragments and can be stably maintained in the organism’s genome.
Other features of cloning vectors include their ability to work under prokaryotic and eukaryotic systems, being small in size so that they can easily integrate into the host cell, and having a restriction site for the insertion of the target DNA.
What is a Plasmid Vector
A plasmid vector is a specific type of cloning vector that is derived from a plasmid and can replicate independently of the chromosomal DNA. They are the first vectors used in gene cloning. These are present in archaea, bacteria, and eukaryotes. These vectors are natural, self-replicating, and extrachromosomal DNA molecules. They also have a high copy number. They possess antibiotic-resistant genes and are circular. In addition, researchers insert DNA fragments or genes into plasmid vectors to create recombinant plasmids.
Plasmids are important in the field of medicine as they carry the genes for pathogenicity and drug resistance. Furthermore, plasmids are inserted into bacteria in a process called transformation. In genetic engineering, researchers artificially prepare plasmids in the laboratory for various purposes.
The structure of plasmid vectors has several important features. One such feature is the selectable marker gene which facilitates the selection of bacterial cells that have taken up the plasmid. Another key feature is the origin of replication which allows the plasmid to replicate independently of the bacterial chromosome. Plasmid vectors also have multiple cloning sites (MCS), which are regions in the plasmid that contain several restriction enzyme recognition sequences.
There are many uses for plasmid molecules. Its most common use is to express genes in bacteria. They are also used in the creation of genetically modified organisms, like transgenic plants or animals.
Difference Between Cloning Vector and Plasmid Vector
Definition
A cloning vector is a DNA molecule that is used to carry foreign DNA fragments into a host cell where they are replicated, while a plasmid vector is a specific type of cloning vector that is derived from a plasmid and can replicate independently from the chromosomal DNA.
Origin of Replication (ORI)
Cloning vectors usually carry a bacterial or viral ORI, whereas plasmid vectors carry their own ORI.
Selectable Markers
While cloning vectors typically carry selectable markers, such as antibiotic-resistant genes, plasmid vectors carry other selectable markers, such as fluorescent proteins or drug-resistant genes.
Replication
Cloning vectors require chromosomal DNA replication machinery to replicate, whereas plasmid vectors have their own replication machinery and can replicate autonomously.
Usage
Moreover, cloning vectors are typically used for cloning and amplifying large DNA fragments, whereas plasmid vectors are often used for expressing proteins or introducing genes into cells for various purposes, such as genetic modification or gene therapy.
Conclusion
The main difference between cloning vector and plasmid vector is that researchers use a cloning vector as a DNA molecule to carry foreign DNA fragments into a host cell where they undergo replication, while a plasmid vector is a specific type of cloning vector that researchers derive from a plasmid, and it can replicate independently from the chromosomal DNA.
Reference:
1. “What is Plasmid?” Akash Byju’s
2. “Cloning Vector – Overview.” Science Direct.
Image Courtesy:
1. “PGEX-3X cloning vector” By Magnus Manske – Created by Magnus Manske. (CC BY-SA 3.0) via Commons Wikimedia
2. “Plasmid vector” (CC0) via Free SVG
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