Introduction

“Gene cloning”- as the term suggests is production of multiple copies of a DNA segment or gene. The process involves introduction of desired gene in a self replicating genetic element to produce recombinant DNA molecule which further multiplies in the host cell to give identical copies of the desired gene.

An Overview

Steps Involved

1.   Hybridization – The fragment of DNA containing the desired gene is inserted in the circular DNA of the vector using restriction enzymes. These restriction enzymes produce sticky ends of the DNA that makes the strands of DNA compatible. Ligase enzyme is used to seal the joints of the recombinant DNA, also called Chimera.

2.   DNA Insertion – The vector act as a vehicle to transfer the gene to the host cell. Various types of living cells can be used as vector but most commonly used vector is bacterium.

3.   Cloning – The host cell divides and produces multiple copies of the recombinant DNA along with its genetic material. When the host cell divide the Gene of interest is transferred to the progeny. A constant process of cell division results in formation of multiple copies of the desired gene and hence the gene is said to be cloned.

Applications

Gene cloning has various applications in different realms of biology. Some of the major applications are discussed below.

1   Protein synthesis is a major field where gene cloning has found its application. Gene cloning is used for synthesizing many therapeutic and pharmaceutical proteins like insulin, interferon and hormones. These biological products have prime importance in medical utility. Gene cloning provides a feasible method to produce bulk of these products. The expression of these proteins in large quantity via the cloning plays an important role biotechnological development. Cloning of stem cells will provide treatment to various diseases.

2.   Gene cloning has played a remarkable role in agriculture. Crop improvement and boost in food production are the two main objectives of cloning. Crop improvement can be done both by introducing a useful gene in crops like nitrogen fixing genes are transferred to some major crops. It can also be done be suppressing the expression of some undesirable genes like blocking the genes responsible for ageing. Several genes in plants as well cattle are manipulated to develop various qualities pest resistance, high milk or crop production etc.

3.   This technique is also used for creating gene library. The gene library contains multiple copies of genes/ genomes, it is possible to identify any specific gene and whenever required any desirable gene can be multiplied by growing in relevant host.  Hence it acts as a store house of genetic material.

Conclusion

Gene cloning has various medical, agricultural and industrial applications but there are certain disadvantages like loss of gene diversity. If gene diversity is lost due to excessive cloning, there are no mutations to allow some of the cloned group to survive a newly introduced disease. It is also a major topic of ethical debate. As every coin has two faces so does this technology have. It is a boon or curse will remain a question in recent future.