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By: Ikedi Ani-okoye.

Cloning explained

Molecular cloning refers to the procedure of isolating a defined DNA sequence and obtaining multiple copies of it in vivo. Cloning is frequently employed to amplify DNA fragments containing genes, but it can be used to amplify any DNA sequence such as promoters, non-coding sequences and randomly fragmented DNA.

It is utilised in a wide array of biological experiments and practical applications such as large scale protein production. Occasionally, the term cloning is misleadingly used to refer to the identification of the chromosomal location of a gene associated with a particular phenotype of interest, such as in positional cloning. In practice, localization of the gene to a chromosome or genomic region does not necessarily enable one to isolate or amplify the relevant genomic sequence.

Types of Cloning

When the media report on cloning in the news, they are usually talking about only one type called reproductive cloning. There are different types of cloning however, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism.

A basic understanding of the different types of cloning is key to taking an informed stance on current public policy issues and making the best possible personal decisions. The following three types of cloning technologies will be discussed: (1) recombinant DNA technology or DNA cloning, (2) reproductive cloning, and (3) therapeutic cloning.

Cloning animal models of disease

• Much of what researchers learn about human disease comes from studying animal models such as mice. Often, animal models are genetically engineered to carry disease-causing mutations in their genes. Creating these transgenic animals is a time-intensive process that requires trial-and-error and several generations of breeding. Cloning technologies might reduce the time needed to make a transgenic animal model, and the result would be a population of genetically identical animals for study.

CONCLUSION

Cloning is often confused with other advances in bio-medicine and bio-engineering - such as genetic selection. It cannot - in itself - be used to produce "perfect humans" or select sex or other traits. Hence, some of the arguments against cloning are either specious or fuelled by ignorance.

It is true, though, that cloning, used in conjunction with other bio-technologies, raises serious bio-ethical questions. Scare scenarios of humans cultivated in sinister labs as sources of spare body parts, "designer babies", "master races", or "genetic sex slaves" - formerly the preserve of B sci-fi movies - have invaded mainstream discourse.