1Department of Pharmaceutical Chemistry, School of Pharmacy, Techno India University, Salt-Lake City, Sector-V, EM-4/1, Kolkata-700091, West Bengal, India
2Deputy Director of Technical Education, Directorate of Technical Education, Bikash Bhavan, Salt Lake City, Kolkata-700091, West Bengal, India
Gene silencing is defined as epigenetic of gene expression leading to inactivation of previously active individual genes or larger chromosome regions. Silencing of a target gene can be achieved at two levels-transcriptional and post-transcriptional stages. The transcriptional gene silencing occurs through the repression of the process of transcription and the post transcriptional gene silencing occurs by the degradation of mRNA. There is also another type called Meiotic. Mechanisms responsible for repression of genes involve changes in level of DNA methylation and alterations in covalent modifications of histone proteins which leads to chromatin compaction. These are the effects of small RNA regulators such as small interfering RNAs (siRNAs), microRNAs (miRNA), Piwi-associated RNAs (piRNAs) etc. Virus can also conduct gene silencing which is known as Virus Induced Gene Silencing by cloning and inserting plant endogenous gene sequence in recombinant viral vectors. Even Gene Silencing helps in buildup resistance against biotic and abiotic stress and helps in knock down any kind of undesirable genes.
Gene silencing, Mirna, Dsrna, RNAi
