Cloning vector (lamda phage vector)
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Lecture about cloning vector which
Lecture about cloning vector which illustrates the properties of lamda phage vector. http://shomusbiology.weebly.com/
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A cloning vector is a small piece of DNA, taken from a virus, a plasmid, or the cell of a higher organism, that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes.[1] The vector therefore contains features that allow for the convenient insertion or removal of DNA fragment in or out of the vector, for example by treating the vector and the foreign DNA with a restriction enzyme that creates the same overhang, then ligating the fragments together. After a DNA fragment has been cloned into a cloning vector, it may be further subcloned into another vector designed for more specific use.
There are many types of cloning vectors, but the most commonly used ones are genetically engineered plasmids. Cloning is generally first performed using Escherichia coli, and cloning vectors in E. coli include plasmids, bacteriophages (such as phage λ), cosmids, and bacterial artificial chromosomes (BACs). Some DNA however cannot be stably maintained in E. coli, for example very large DNA fragment, and other organisms such as yeast may be used. Cloning vectors in yeast include yeast artificial chromosomes (YACs).
The bacteriophages used for cloning are the phage λ and M13 phage. There is an upper limit on the amount of DNA that can be packed into a phage (a maximum of 53 kb), therefore to allow foreign DNA to be inserted into phage DNA, phage cloning vectors need to have some non-essential genes deleted, for example the genes for lysogeny in phage λ.[15] There are two kinds of λ phage vectors - insertion vector and replacement vector. Insertion vectors contain a unique cleavage site whereby foreign DNA with size of 5--11 kb may be inserted. In replacement vectors, the cleavage sites flank a region containing genes not essential for the lytic cycle, and this region may be deleted and replaced by the DNA insert in the cloning process, and a larger sized DNA of 8--24 kb may be inserted.[16]
There is also a lower size limit for DNA that can be packed into a phage, and vector DNA that is too small cannot be properly packaged into the phage. This property can be used for selection - vector without insert may be too small, therefore only vectors with insert may be selected for propagation. Source of the article published in description is Wikipedia. I am sharing their material. Copyright by original content developers of Wikipedia.
Link- http://en.wikipedia.org/wiki/Main_Page
Download the study materials here-
http://shomusbiology.weebly.com/bio-m...
A cloning vector is a small piece of DNA, taken from a virus, a plasmid, or the cell of a higher organism, that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes.[1] The vector therefore contains features that allow for the convenient insertion or removal of DNA fragment in or out of the vector, for example by treating the vector and the foreign DNA with a restriction enzyme that creates the same overhang, then ligating the fragments together. After a DNA fragment has been cloned into a cloning vector, it may be further subcloned into another vector designed for more specific use.
There are many types of cloning vectors, but the most commonly used ones are genetically engineered plasmids. Cloning is generally first performed using Escherichia coli, and cloning vectors in E. coli include plasmids, bacteriophages (such as phage λ), cosmids, and bacterial artificial chromosomes (BACs). Some DNA however cannot be stably maintained in E. coli, for example very large DNA fragment, and other organisms such as yeast may be used. Cloning vectors in yeast include yeast artificial chromosomes (YACs).
The bacteriophages used for cloning are the phage λ and M13 phage. There is an upper limit on the amount of DNA that can be packed into a phage (a maximum of 53 kb), therefore to allow foreign DNA to be inserted into phage DNA, phage cloning vectors need to have some non-essential genes deleted, for example the genes for lysogeny in phage λ.[15] There are two kinds of λ phage vectors - insertion vector and replacement vector. Insertion vectors contain a unique cleavage site whereby foreign DNA with size of 5--11 kb may be inserted. In replacement vectors, the cleavage sites flank a region containing genes not essential for the lytic cycle, and this region may be deleted and replaced by the DNA insert in the cloning process, and a larger sized DNA of 8--24 kb may be inserted.[16]
There is also a lower size limit for DNA that can be packed into a phage, and vector DNA that is too small cannot be properly packaged into the phage. This property can be used for selection - vector without insert may be too small, therefore only vectors with insert may be selected for propagation. Source of the article published in description is Wikipedia. I am sharing their material. Copyright by original content developers of Wikipedia.
Link- http://en.wikipedia.org/wiki/Main_Page
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