Transcription-mediated mutagenic processes

Abstract

During growth, DNA is stable, easily repaired, replicated with high fidelity, and stably passed from generation to generation. Cellular division and growth require that DNA be replicated, transcribed, and translated. For several decades, the study of DNA metabolism has uncovered a vast number of mechanisms that generate mutations and promote evolution. While all DNA in a cell has to be replicated, the act of transcription is reduced to a subset of genes required for essential growth, or occurs in response to an environmental cue. Transcripts are then processed or translated to functional entities, which allow cell growth and adaptation to beneficial or detrimental conditions. While this view limits RNA to transient functions in the cell, our understanding of RNA metabolism in recent years has progressed from being a mere informational intermediate step in the central dogma to becoming a factor that mediates the production of genetic diversity, which modifies the genetic makeup of future generations and accelerates evolution. Here, we briefly review how gene transcriptional activation is coupled with mutagenic pathways; these processes are novel and improve our understanding of the evolutionary process.