REVERSE GENETICS

In classic genetics, the traditional approach was to find a gene product and then try to identify the gene itself. In molecular genetics, the reverse has been done by identifying genes purely on the basis of their position in the genome with no knowledge whatsoever of the gene product. This revolutionary approach is reverse genetics.
Reverse genetics is an approach to discovering the function of a gene by analyzing the phenotypic effects of specific gene sequences obtained by DNA sequencing.
Through genetic analyses, the function of genes is investigated by studying organisms where gene function is altered. In classical forward genetic screening, individuals are treated with mutagens to induce DNA lesions and mutants with a phenotype of interest are sought. After a mutant is found, the gene mutated is identified through standard molecular techniques. Detailed studies of the mutant phenotype coupled with molecular analyses of the gene allows elucidation of the gene's function. Forward genetics has been responsible for our understanding of many biological processes and is an excellent method for identifying genes that function in a particular process.In reverse genetics, the functional study of a gene starts with the gene sequence rather than a mutant phenotype.