Author: Forterre, Patrick
Description: Viruses infecting cells from the three domains of life, Archaea, Bacteria and Eukarya, share homologous features, suggesting that viruses originated very early in the evolution of life. The three current hypotheses for virus origin, e.g. the virus first, the escape and the reduction hypotheses are revisited in this new framework. Theoretical considerations suggest that RNA viruses may have originated in the nucleoprotein world by escape or reduction from RNA-cells, whereas DNA viruses (at least some of them) might have evolved directly from RNA viruses. The antiquity of viruses can explain why most viral proteins have no cellular homologues or only distantly related ones. Viral proteins have replaced the ancestral bacterial RNA/DNA polymerases and primase during mitochondrial evolution. It has been suggested that replacement of cellular proteins by viral ones also occurred in early evolution of the DNA replication apparatus and/or that some DNA replication proteins originated directly in the virosphere and were later on transferred to cellular organisms. According to these new hypotheses, viruses played a critical role in major evolutionary transitions, such as the invention of DNA and DNA replication mechanisms, the formation of the three domains of life, or else, the origin of the eukaryotic nucleus.
Subject headings: Virus; Evolution; RNA; Origin; DNA; Archaea; Bacteria; Eukarya
Publication year: 2006
Journal or book title: Virus Research
Volume: 117
Issue: 1
Pages: 5–16
Find the full text: https://www.sciencedirect.com/science/article/pii/S0168170206000293
Find more like this one (cited by): https://scholar.google.com/scholar?cites=9492784703860617390&as_sdt=1000005&sciodt=0,16&hl=en
Type: Journal article
Serial number: 3153