GENETIC ENGINERING

Moreover, for centuries human being have been altering the genetic make up of organisms by selective breeding of plant and animals. The deliberate modification in genetic material of an organism by changing the nucleic acid directly is called genetic engineering or gene cloning or gene manipulation and is accomplished by several methods which are collectively known as recombinat DNA (rDNA) technology. Recombinant DNA technology begins a new area of research and applied aspects of biology. Therefore, it is a part of biotechnology which is gaining momentum and much boost in recent years.

However, in breeding programmes much work has been done on alteration of nucleotides by several parasexual or conjugation methods indifferent group of organisms. Now –a-day, a large number of mutagenic agents are available that mutate the genes. It is likely that the changed genes may be beneficial, neutral or lethal. Moreover, the conventional breeding programmes are time taking for making sure that the genes have been altered. In contrast, the rDNA technology has solved several problems which hardly or never are possible through the conventional methods.

Gene cloning or genetic engineering can be defined as changing of genes by using in vitro processes. A unified definition of genetic engineering has been given by smith (1996) as the formation of new combinations of heritable material by the insertion of nucleic acid molecules produced by whatever means outside the cell, into any virus, bacterial plasmid or other vector system so as to allow their incorporation into a host organism in which they do not naturally occur but in which they are capper of continued propagation. In brief, gene technology is the modification of the genetic properties of an organism by sing rDNA technology. Genes are like the biological software filled with programme that govern the growth, development and function of organism. By changing in programme of the software it is possible to bring about alteration in the characters of a given organism (smith,1996).

A gene of known function can be isolated from its normal location by biochemical methods in vitro. Moreover, a gene can be synthesized by using gene machine. The isolated genes can be transferred into the microbial cells (that of course do not contain) via a suitable vector. The transferred gene replicates normally and is handed over to the next progeny over generations. After confirmation for its presence through biochemical procedures clone of the same cell is produced.