Noncoding RNAs: Persistent Viral Agents as Modular Tools for Cellular Needs

摘要

It appears that all the detailed steps of evolution stored in DNA that are read, tran-scribed, and translated in every developmental and growth process of each individualcell depend on RNA-mediated processes, in most cases interconnected with other RNAsand their associated protein complexes and functions in a strict hierarchy of temporaland spatial steps. Life could not function without the key agents of DNA replication,namely mRNA, tRNA, and rRNA. Not only rRNA, but also tRNA and the processing ofthe primary transcript into the pre-mRNA and the mature mRNA are clearly descendedfrom retro-"elements" with obvious retroviral ancestry. They seem to be remnants ofviral infection events that did not kill their host but transferred phenotypic competencesto their host and changed both the genetic identity of the host organism and the identityof the former infectious viral swarms. In this respect, noncoding RNAs may representa great variety of modular tools for cellular needs that are derived from persistentnonlytic viral settlers.