when we hear the name Dolly — the Sheep what cones to our mind is Cloning. DNA cloning also known as molecular cloning, gene cloning and recombinant DNA technology – refers to the process of creating multiple copies of an isolated DNA fragment or fragments by in vitro or in vivo methods. It is possible to clone entire gene fragments, random portions of DNA fragments or specific DNA sequences. There are three major types of DNA cloning procedures.
Embryo cloning is a medical technique which produces monozygotic (identical) twins or triplets. It duplicates the process that nature uses to produce twins or triplets. One or more cells are removed from a fertilized embryo and encouraged to develop into one or more duplicate embryos. Twins or triplets are thus formed, with identical DNA. Adult DNA cloning also known as reproductive cloning is a technique which is intended to produce a duplicate of an existing animal. It has been used to clone a sheep and other mammals. The third type is Therapeutic cloning or biomedical cloning, a procedure whose initial stages are identical to adult DNA cloning. However, the stem cells are removed from the pre-embryo with the intent of producing tissue or a whole organ for transplant back into the person who supplied the DNA.
There are many arguments against DNA cloning, including the loss of identity and individuality, and human diversity. With therapeutic cloning, not only do the above issues apply, but also the moral and religious issues related to the willful killing of human embryos. Maybe the greatest concern of all is that man would simply become another designer based product. But the silver lining in DNA cloning is that it is helpful in getting an insight into an organism’s genetic make-up and how this affects and influences the organism’s life processes. DNA cloning is being used in genetic finger-printing; in genetic engineering to create plants with better nutritional value, or better resistance to diseases and animals with desirable genetic features and in protein production. Recombinant DNA technology has produced over 100 products for human health therapy, such as: insulin for diabetics, drugs such as factor VIII and factor IX for hemophilia A and B, and erythropoietin for treating Anemia.