PT - JOURNAL ARTICLE AU - Lincoln, Tracey A. AU - Joyce, Gerald F. TI - Self-Sustained Replication of an RNA Enzyme DP - 2009 Feb 27 TA - Science PG - 1229--1232 VI - 323 IP - 5918 4099 - http://science.sciencemag.org/content/323/5918/1229.short 4100 - http://science.sciencemag.org/content/323/5918/1229.full SO - Science2009 Feb 27; 323 AB - An RNA enzyme that catalyzes the RNA-templated joining of RNA was converted to a format whereby two enzymes catalyze each other's synthesis from a total of four oligonucleotide substrates. These cross-replicating RNA enzymes undergo self-sustained exponential amplification in the absence of proteins or other biological materials. Amplification occurs with a doubling time of about 1 hour and can be continued indefinitely. Populations of various cross-replicating enzymes were constructed and allowed to compete for a common pool of substrates, during which recombinant replicators arose and grew to dominate the population. These replicating RNA enzymes can serve as an experimental model of a genetic system. Many such model systems could be constructed, allowing different selective outcomes to be related to the underlying properties of the genetic system.