Can Introns Stabilize Gene Duplication?

SIMPLE SUMMARY: Eukaryotic genes are organized as DNA sequences containing exon and intron regions. Exons relate to sequences that, after transcription, will be maintained in mature mRNA to provide the blueprint for protein translation. Introns, on the other hand, are present in the primary transcript and are then removed by the splicing mechanisms. The evolutionary solutions that maintain and make this complex gene organization functional are only partially known. Here, we speculate that the presence of introns in the gene sequence can stabilize the products of gene duplication, one of the most effective driving forces in genome evolution. The hypothesis we propose is to be considered additional to those currently reported and not as an alternative. ABSTRACT: Gene duplication is considered one of the most important events that determine the evolution of genomes. However, the neo-duplication condition of a given gene is particularly unstable due to recombination events. Several mechanisms have been proposed to justify this step. In this “opinion article” we propose a role for intron sequences in stabilizing gene duplication by limiting and reducing the identity of the gene sequence between the two duplicated copies. A review of the topic and a detailed hypothesis are presented.