DNA cloning is the starting point for many genetic engineering approaches to biotechnology research.
Large amounts ofare needed for . Multiple copies of a piece of DNA can be made either by using Polymerase Chain Reaction (PCR) or by cloning DNA in cells.
What Is DNA Cloning?
When you hear the word ‘clone’, you may think of a weird sci-fi movie, or perhaps something more realistic, like Dolly the sheep. But DNA cloning goes far beyond this. DNA cloning, which is the production of multiple identical copies of a DNA fragment, is responsible for all sorts of things, such as pest-resistant plants, bacteria used for toxic waste cleanup, and even ‘stone-washed’ jeans. That’s right; no actual stones were used to create that look, just enzymes that are cloned from bacteria!
Overview of DNA cloning
How is DNA cloned in cells?
To get multiple copies of a replicate (or copy) itself.or other piece of DNA you must isolate, or ‘cut’, the DNA from its source and then ‘paste’ it into a DNA that can
The four main steps in DNA cloning are:
Step 1. The chosen piece of DNA is ‘cut’ from the source organism using restriction enzyimes.
Step 2. The piece of DNA is ‘pasted’ into a vector and the ends of the DNA are joined with the vector DNA by ligation.
Step 3. The vector is introduced into a host cells copy the vector DNA along with their own DNA, creating multiple copies of the inserted DNA., often a bacterium or , by a process called transformation. The
Step 4. The vector DNA is isolated (or separated) from the host cells’ DNA and purified.
DNA that has been ‘cut’ and ‘pasted’ from an organism into a vector is called recombinant DNA. Because of this, DNA cloning is also called recombinant DNA technology.
What is cloned DNA used for?
DNA cloning is used to create a large number of copies of a gene or other piece of DNA. The cloned DNA can be used to:
- Work out the function of the gene
- Investigate a gene’s characteristics (size, expression, tissue distribution)
- Look at how mutations may affect a gene’s function
- Make large concentrations of the coded for by the gene
What other types of cloning are there?
The term ‘cloning’ is also used to describe other laboratory processes:
- Reproductive cloning is the process of making a genetically identical copy of an organism.
- Therapeutic cloning is the process of making multiple copies of a cell to treat a disease.
Uses of DNA cloning
Biopharmaceuticals. DNA cloning can be used to make human proteins with biomedical applications, such as the insulin mentioned above. Other examples of recombinant proteins include human growth hormone, which is given to patients who are unable to synthesize the hormone, and tissue plasminogen activator (tPA), which is used to treat strokes and prevent blood clots. Recombinant proteins like these are often made in bacteria.
Gene therapy. In some genetic disorders, patients lack the functional form of a particular gene. Gene therapy attempts to provide a normal copy of the gene to the cells of a patient’s body. For example, DNA cloning was used to build plasmids containing a normal version of the gene that’s nonfunctional in cystic fibrosis. When the plasmids were delivered to the lungs of cystic fibrosis patients, lung function deteriorated less quickly^22start superscript, 2, end superscript.
Gene analysis. In basic research labs, biologists often use DNA cloning to build artificial, recombinant versions of genes that help them understand how normal genes in an organism function.
The legalities on human cloning differ around the world. In the U.S., human cloning is only explicitly outlawed in eight states. According to the Bioethics Defense Fund, an additional four states simply prohibit state funding of human cloning and 10 states allow human embryos to be cloned but ban the embryo from being allowed to mature full term (thus outlawing reproductive cloning but allowing therapeutic cloning). The international stance on cloning is clearer, with the United Nations General Assembly banning all forms of human cloning in 2005, including both reproductive and therapeutic.
For these legal reasons as well as ethical reasons, it’s probable that the future of cloning will lie more in therapeutic cloning research than reproductive cloning. The only difference between therapeutic cloning and reproductive cloning is that in therapeutic cloning the embryo is never transferred into a female’s womb. The current goals for therapeutic cloning are a means to develop both patient and disease specific therapies for certain conditions. The procedure could also potentially use a patient’s own cells for tissue replacement. Although the science is exciting, it will likely take many decades of research before scientists are able to create transplant-able tissue.