The process of cloning is the asexual reproduction of the same exact copy of an original. This cell copy is identical to the first cell, with the exact same DNA sequence. Biotechnology cloning is the intentional cloning of entire organisms or part of the DNA or organism. There are three main biotechnology types of cloning: reproductive cloning, therapeutic cloning, and DNA cloning.
Reproductive cloning is performed for the purpose of creating a duplicate copy of another organism. A process called somatic cell nuclear transfer is used. During somatic cell nuclear transfer, the nucleus is extracted from a somatic cell. This cell can come from anywhere in the organism’s body. The nucleus is then inserted into an egg that has had its nucleus removed. The egg is stimulated and begins to divide and grow. It will develop into an embryo. which is then implanted into a gestational surrogate carried to term.
There have been issues with reproductive cloning. Clones seem to have shorter lifespans, creating concern about this type of cloning. Also, the risk of losing genetic diversity is great, especially within the agricultural industry.
Therapeutic cloning is used for the purpose of medical treatment. It can be used to grow a replacement organ, generate skin for a burn victim, or create nerve cells for someone suffering from brain damage. As in reproductive cloning, the process used is somatic cell nuclear transfer. The difference in therapeutic cloning is that the growing egg is used as a source of stem cells. Stems cells are undifferentiated cells that can grow into a wide variety of different types of cells.
Therapeutic cloning has an advantage in medical treatment. Doctors can grow replacements for missing and damaged body parts for their patients. This could eliminate the need for immunosuppressive drugs and reduce the risk of the body rejecting the replacement organ.
DNA cloning is used to create multiple copies of an isolated DNA fragment or fragments by in vitro or in vivo methods. The several cloning possibilities include cloning an entire gene fragment, random portions of DNA fragments, and specific DNA sequences.
The DNA cloning process begins by isolating a DNA fragment or fragments of interest from the chromosomal DNA, using restriction enzymes or chemically synthesized oligonucleotides. Polymerase chain reaction (PCR), agarose gel electrophoresis, and DNA sonication are additional methods used for DNA cloning.
DNA cloning is used in genetic fingerprinting; in genetic engineering to create better nutritional value in plants; and to create animals with desirable genetic features. It is also a helpful insight into an organism’s genetic make-up and how it affects and influences the organism’s life processes.
Reproductive Health Technologies Project: Reproductive Cloning - www.rhtp.org/fertility/cloning/default.asp
Cell Medicine: Therapeutic Cloning - www.cellmedicine.com/cloning.asp
Microbial Life: Cloning - https://serc.carleton.edu/microbelife/research_methods/genomics/clonevec.html