This year, the Nobel prize for medicine has been conferred on two Americans, Andrew Z Fire of the MIT and Craig C Mello of
the Harvard University, for their discovery of ‘RNA
interference’, a catalytic process proposed to occur in plants, animals and humans.
As is well known, the DNA contains the basic information related to life. There are thousands of genes in our genome, but they are selectively expressed to produce the mRNA through a process called ‘transcription’, which is regulated by several factors.
Fire and Mello carried out their study on a nematode worm called, Caenorhabditis elegans. Injecting these worms with ‘sense’ mRNA or RNA strand that had complementary base pairs to the
transcribing DNA, or injecting them with the ‘antisense’ RNA or that which had identical base pairs to the transcribing DNA, did not elicit a response from these nematodes. However when the ‘sense’ and the ‘anti sense’ RNA strands were injected together, the worm displayed peculiar twitching or wriggling movements. It was later discovered that the ‘sense’ and the ‘anti sense’ RNAs paired and formed double stranded RNA that activated the RNA interference machinery and silenced the gene whose codes matched that of the injected RNA, resulting in the corresponding protein not being produced. Fire and Mello have published their work in the February edition of Nature, 1998.These scientists, who have a PhD in biology, have simplified the understanding of the mechanism involved in the flow of genetic information besides clarifying several complicated experimental observations. The scientists have proposed that very little double stranded RNA is required to produce RNAi, which can spread from cell to cell and may be inherited.
RNA interference is an exciting research tool which has opened up new vistas in the field of gene technology and if used in clinical medicine, like cardiology and oncology, promotes exciting possibilities of a healthier tomorrow.