Document Type

Article

Publication Date

3-31-2017

Subjects

Catalytic RNA, Proteins -- Evolution, Evolutionary genetics

Abstract

An RNA-directed recombination reaction can result in a network of interacting RNA species. It is now becoming increasingly apparent that such networks could have been an important feature of the RNA world during the nascent evolution of life on the Earth. However, the means by which such small RNA networks assimilate other available genotypes in the environment to grow and evolve into the more complex networks that are thought to have existed in the prebiotic milieu are not known. Here, we used the ability of fragments of the Azoarcus group I intron ribozyme to covalently self-assemble via genotype-selfish and genotype-cooperative interactions into full-length ribozymes to investigate the dynamics of small (three- and four-membered) networks. We focused on the influence of a three-membered core network on the incorporation of additional nodes, and on the degree and direction of connectivity as single new nodes are added to this core. We confirmed experimentally the predictions that additional links to a core should enhance overall network growth rates, but that the directionality of the link (a “giver” or a “receiver”) impacts the growth of the core itself. Additionally, we used a simple mathematical model based on the first-order effects of lower-level interactions to predict the growth of more complex networks, and find that such a model can, to a first approximation, predict the ordinal rankings of nodes once a steady-state distribution has been reached.

Description

© 2017 Yeates et al.

This article is distributed exclusively by the RNA Society for the first 12 months after the full-issue publication date (see http:// rnajournal.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 Inter- national), as described at http://creativecommons.org/licenses/by-nc/4.0/.

Locate the Document

Article is available online at: http://www.rnajournal.org/cgi/doi/10.1261/rna.061093.117

DOI

10.1261/rna.061093.117

Persistent Identifier

http://archives.pdx.edu/ds/psu/22521

Available for download on Saturday, March 31, 2018

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