Characteristics of post-transcriptional gene silencing

A number of gene silencing phenomena that inactivate genes at the post-tran scriptional level have been identified. Due to its potential for studying g ene function, post-transcriptional gene silencing (PTGS) has become an inte nse area of research. In this review we describe the different means of ind ucing PTGS and discuss the possible biological roles of these artificially induced phenomena. We also discuss other features of PTGS such as the mecha nism of mRNA degradation, the nature of the silencing signal and the mechan ism of PTGS inhibition by viral proteins.