What is gene silencing?
Q: What is gene silencing?
A: Gene silencing is a general term describing epigenetic processes of gene regulation. It is used to describe the "switching off" of a gene by a mechanism other than genetic engineering, meaning that a gene which would be expressed ("turned on") under normal circumstances is switched off by machinery in the cell. When a gene is silenced it means that its RNA is unable to make a protein.
Q: How does transcriptional gene silencing work?
A: Transcriptional gene silencing works by histone modifications, which put heterochromatin around a gene. This means the transcriptional machinery (RNA polymerase, transcription factors, etc.) cannot get at the gene. Genes may also be silenced by DNA methylation.
Q: How does post-transcriptional gene silencing work?
A: Post-transcriptional gene silencing works by blocking or destroying the mRNA of a particular gene. The destruction of the mRNA prevents translation to form an active gene product (in most cases, a protein). A common way mRNA gets silenced is through RNAi.
Q: What are some methods used for regulating genes?
A: Both transcriptional and post-transcriptional methods can be used for regulating genes. Methods of gene silencing also protect the organism's genome from transposons and viruses.
Q: What purpose does Gene Silencing serve?
A: Gene Silencing serves multiple purposes including regulating genes and protecting cells from infectious DNA and RNA as part of an ancient immune system.
Q: Is DNA methylation involved in Gene Silencing?
A: Yes, DNA methylation can be involved in Gene Silencing as it regularly happens during development when genes are turned on and off at different stages
