2006/07/21 by Francisco Rodrı́guez-Trelles, Rosa Tarrı́o, Francisco J. Ayala · 6 citations
Biochemistry, Genetics and Molecular Biology · #RNA Research and Splicing #RNA and protein synthesis mechanisms #RNA modifications and cancer
paper · doi:10.1146/annurev.genet.40.110405.090625
openalex publication_date 2006/07/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Research into the origins of introns is at a critical juncture in the resolution of theories on the evolution of early life (which came first, RNA or DNA?), the identity of LUCA (the last universal common ancestor, was it prokaryotic- or eukaryotic-like?), and the significance of noncoding nucleotide variation. One early notion was that introns would have evolved as a component of an efficient mechanism for the origin of genes. But alternative theories emerged as well. From the debate between the "introns-early" and "introns-late" theories came the proposal that introns arose before the origin of genetically encoded proteins and DNA, and the more recent "introns-first" theory, which postulates the presence of introns at that early evolutionary stage from a reconstruction of the "RNA world." Here we review seminal and recent ideas about intron origins. Recent discoveries about the patterns and causes of intron evolution make this one of the most hotly debated and exciting topics in molecular evolutionary biology today.