Ravi Kumar

By Jitesh Kumar, Khushbu Jain, Priyanka Kumari, Auroshikha Mohanty, Kumari Rajani, Ravi Ranjan Kumar and Tushar Ranjan

In the course of transgenic experiments on the nematode Caenorhabditis elegans, RNA interference, usually abbreviated as RNAi, was discovered first. It is a gene-silencing effect and is found to be widely distributed in eukaryotes. It was observed that control injections of sense RNA were just as effective as antisense RNA, directed at specifically inhibiting target genes in C. elegans by the injection of antisense RNA during an experiment causing the reduction or elimination of expression from the gene under investigation. Subsequently, by injecting double-stranded RNA (dsRNA) corresponding to the target gene, it was discovered that the effect could be most potently elicited, and contamination of the single-stranded RNA (ssRNA; either sense or antisense) by traces of dsRNA could explain the earlier results. By post-transcriptional mechanism, substantial or complete inhibition of expression from any gene can be done using dsRNA corresponding to part or all of the mature mRNA from any given gene. An attempt was made here to describe the basic underlying molecular mechanism of RNAi, the methodology and various experimental requirements, and its advantages and disadvantages. In relation to CRISPR/Cas9 technology, the future prospects of virus-induced gene silencing (VIGS) are considered finally. For the cutting-edge CRISPR/Cas9 genome editing technology, VIGS has emerged as the preferred delivery system besides using it to overexpress or silence genes.

Part of the book: Genetic Transformation in Crops