Publication Date:
2009-03-07
Description:
The mutation rates of viroids, plant pathogens with minimal non-protein-coding RNA genomes, are unknown. Their replication is mediated by host RNA polymerases and, in some cases, by hammerhead ribozymes, small self-cleaving motifs embedded in the viroid. By using the principle that the population frequency of nonviable genotypes equals the mutation rate, we screened for changes that inactivated the hammerheads of Chrysanthemum chlorotic mottle viroid. We obtained a mutation rate of 1/400 per site, the highest reported for any biological entity. Such error-prone replication can only be tolerated by extremely simple genomes such as those of viroids and, presumably, the primitive replicons of the RNA world. Our results suggest that the emergence of replication fidelity was critical for the evolution of complexity in the early history of life.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gago, Selma -- Elena, Santiago F -- Flores, Ricardo -- Sanjuan, Rafael -- New York, N.Y. -- Science. 2009 Mar 6;323(5919):1308. doi: 10.1126/science.1169202.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia, 46022 Valencia, Spain.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19265013" target="_blank"〉PubMed〈/a〉
Keywords:
Genome, Viral
;
Molecular Sequence Data
;
*Mutation
;
Nucleic Acid Conformation
;
RNA, Catalytic/chemistry/*genetics
;
RNA, Viral/chemistry/*genetics
;
Replicon
;
Reverse Transcriptase Polymerase Chain Reaction
;
Selection, Genetic
;
Viroids/*genetics/physiology
;
Virus Replication
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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