An Overview of the Introns-First Theory

@article{Penny2009AnOO,
  title={An Overview of the Introns-First Theory},
  author={David Penny and Marc P. Hoeppner and Anthony M. Poole and Daniel C. Jeffares},
  journal={Journal of Molecular Evolution},
  year={2009},
  volume={69},
  pages={527-540}
}
We review the introns-first hypothesis a decade after it was first proposed. It is that exons emerged from non-coding regions interspersed between RNA genes in an early RNA world, and is a subcomponent of a more general ‘RNA-continuity’ hypothesis. The latter is that some RNA-based systems, especially in RNA processing, are ‘relics’ that can be traced back either to the RNA world that preceded both DNA and encoded protein synthesis or to the later ribonucleoprotein (RNP) world (before DNA took… 
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