Technology and biomedical research have resulted to a new field of life creation. Cloning refers to the process of developing new plants or animals or part of them that are genetically identical to the original organism. There are three types of cloning namely; DNA cloning, reproductive cloning and Therapeutic cloning. The basic distinction of the cloning is both cell component involved in clones and intention of cloning. There are several claims of animals which have been successfully cloned since the cloning of the first cloned sheep in 1997. According to National Research Council, “evidence on cloning of human beings is only witnessed at the level of therapeutic cloning and DNA cloning levels” (23).
DNA cloning is also known as gene cloning molecular cloning or DNA technology. In DNA cloning the DNA the researchers generate multiple copies of the DNA strand fragment(s). The fragment section of the DNA will be multiplied and modified to suit the need of the researchers. Effective DNA cloning depends with a “selectively amplifiable DNA fragment which can be purified essentially to homogeneity” (Strachan and Read 1999). Amplification process will result to programmed ample number of copy codes of the selected sequence. The process may either be Cell- based DNA cloning where DNA fragments selected are propagated in the cells of a living organism. The second type is Cell-free DNA cloning where is entirely in vitro. The process is enzyme mediated approach and is commonly referred to as Polymerase Chain Reaction (PCR).Want an expert to write a paper for you Talk to an operator now
The process of DNA cloning constitute four key steps, though not constant but in all the DNA cloning approaches the process has undergoes these common steps. The first approach is the formation of recombinant DNA where DNA fragments are isolated from targeted DNA strand. The second step involves construction of recombinant DNA fragments to form the required targeted DNA components. The step involves the use of endonucleases enzymes to separate the segment and DNA ligases enzymes to co-join the separate fragments. The resultant replicon is then introduced in to the cell initiating for DNA multiplication. After successful multiplication, the cells are then isolated to develop separate DNA strands identical to the original sources. “Effective DNA cloning requires a cell component that is capable of replicating.” (Strachan and Read 1999). Polymerase chain reaction is then employed to confirm genetically identity of the new DNA created.
The second category of cloning is reproductive cloning. Reproductive cloning involves creating organisms that are identical to already existing organisms). Ideally, the egg is supposed to divide and duplicate resulting to a new organism. This is the process that is employed in reproductive cloning. Reproductive cloning involves two approaches; Cloning using somatic cell nuclear transfer (SCNT) and cloning by embryo splitting. The first approaches involve enucleating an egg and nucleating it with components of the somatic cell. The genetic materials from the donor egg are excavated and replaces with the nucleus of a somatic cell from the targeted organism. It is possible to obtain the cells from either a living organism or stored body cells. The new generated egg cell is then stimulated to initiate division, just like the normal egg cell. The cell divides to form blastocysts “which are then transferred into the Uterus” (National Research Council, 25) where it is allowed to grow into an embryo through fetus. In this case, genetic identity will be restricted to the composition of the using the same source of both the egg and the somatic cell. Where the donated egg receives nuclear from a somatic cell of the same individual, the embryo will be utterly identical since “it has received all its genetic material from single individual” (National Research Council 25).
In the second approach, cloning by embryo splitting, the egg is fertilized outside the body of the receiver (in vitro fertilization). The cells are allowed to divide up to the stage where the form a total of four cells. The cells are then split onto two groups, which are introduced into the Uterus of the receiver. The two will grow to form identical organism with same genetic composition of each other. However, though the clones have identical genetic composition, behavior and physical characteristic may differ since the two are prone to nurture influence.
The last class of cloning is therapeutic cloning, which is performed with the intension of medical treatment purposes. In therapeutic cloning, the procedure involves the use of somatic cell nuclear to replace the content of the egg cell components. The procedures follow that of reproductive, though the intention is not to grow a new organism, but rather form a given section of the body tissue. Murnaghan comments that an “ideal examples of therapeutic cloning are witnessed in stem cell transplant treatment” (Murnaghan 2012), which has won favor in a number of cases.
The idea of embryonic cell ability to differentiate to different cell types forms the basic concept in therapeutic cloning. The genetic materials from the egg cell are removed and replaced with those of the targeted somatic cells. After the new cell has divided to form an embryo cell, the cell is then injected into the targeted tissues in the body where it divides to yield new tissue composition similar to those of the new environment. The fact that extraction of stem cells from the embryo cell destroys, and to some point kills the developing embryo has raised controversies over the morality of the procedure. According to Murnaghan therapeutic cloning is “requires ample attempts to create viable eggs, and this poses a considerable challenge for this technology.
In conclusion, cloning process is classified into three classes depending with the targeted cell and the intention of the resulting product. The technology has led to ample improvement in the medical field, despite raising considerable controversies.