Abstract
Mutations and their effects on fitness are a fundamental component of evolution. The effects of some mutations change in the presence of other mutations, and this is referred to as epistasis. Epistasis can occur between mutations in different genes or within the same gene. A systematic study of epistasis requires the analysis of numerous mutations and their combinations, which has recently become feasible with advancements in DNA synthesis and sequencing. Here we review the mutational effects and epistatic interactions within RNA molecules revealed by several recent high-throughput mutational studies involving two ribozymes studied in vitro, as well as a tRNA and a snoRNA studied in yeast. The data allow an analysis of the distribution of fitness effects of individual mutations as well as combinations of two or more mutations. Two different approaches to measuring epistasis in the data both reveal a predominance of negative epistasis, such that higher combinations of two or more mutations are typically lower in fitness than expected from the effect of each individual mutation. These data are in contrast to past studies of epistasis that used computationally predicted secondary structures of RNA that revealed a predominance of positive epistasis. The RNA data reviewed here are more similar to that found from mutational experiments on individual protein enzymes, suggesting that a common thermodynamic framework may explain negative epistasis between mutations within macromolecules.




Similar content being viewed by others
References
Bershtein S, Segal M, Bekerman R et al (2006) Robustness-epistasis link shapes the fitness landscape of a randomly drifting protein. Nature 444:929–932. https://doi.org/10.1038/nature05385
Bloom JD, Arnold FH (2009) Colloquium papers: in the light of directed evolution: pathways of adaptive protein evolution. Proc Natl Acad Sci 106:9995–10000. https://doi.org/10.1073/pnas.0901522106
Bloom JD, Wilke CO, Arnold FH, Adami C (2004) Stability and the evolvability of function in a model protein. Biophys J 86:2758–2764. https://doi.org/10.1016/S0006-3495(04)74329-5
Bonhoeffer S, Chappey C, Parkin NT et al (2004) Evidence for positive epistasis in HIV-1. Science 306:1547–1550. https://doi.org/10.1126/science.1101786
Chakshusmathi G, Kim SD, Rubinson DA, Wolin SL (2003) A La protein requirement for efficient pre-tRNA folding. EMBO J 22:6562–6572. https://doi.org/10.1093/emboj/cdg625
Cherry JM, Hong EL, Amundsen C et al (2012) Saccharomyces genome database: the genomics resource of budding yeast. Nucleic Acids Res 40:D700–D705. https://doi.org/10.1093/nar/gkr1029
de la Iglesia F, Elena SF (2007) Fitness declines in tobacco etch virus upon serial bottleneck transfers. J Virol 81:4941–4947. https://doi.org/10.1128/JVI.02528-06
Desai MM, Fisher DS, Murray AW (2007) The speed of evolution and maintenance of variation in asexual populations. Curr Biol 17:385–394. https://doi.org/10.1016/j.cub.2007.01.072
Elena SF, Lenski RE (1997) Test of synergistic interactions among deleterious mutations in bacteria. Nature 390:395–398. https://doi.org/10.1038/37108
Eyre-Walker A, Keightley PD (2007) The distribution of fitness effects of new mutations. Nat Rev Genet 8:610–618. https://doi.org/10.1038/nrg2146
Fenster CB, Galloway LF, Chao L (1997) Epistasis and its consequences for the evolution of natural populations. Trends Ecol Evol 12:282–286
Halligan DL, Keightley PD (2009) Spontaneous mutation accumulation studies in evolutionary genetics. Annu Rev Ecol Evol Syst 40:151–172
Halls C, Mohr S, Del Campo M et al (2007) Involvement of DEAD-box proteins in group I and group II intron splicing. Biochemical characterization of Mss116p, ATP hydrolysis-dependent and-independent mechanisms, and general RNA chaperone activity. J Mol Biol 365:835–855
Hayden EJ, Riley CA, Burton AS, Lehman N (2005) RNA-directed construction of structurally complex and active ligase ribozymes through recombination. RNA 11:1678–1687. https://doi.org/10.1261/rna.2125305
Hayden EJ, Bendixsen DP, Wagner A (2015) Intramolecular phenotypic capacitance in a modular RNA molecule. Proc Natl Acad Sci. https://doi.org/10.1073/pnas.1420902112
He X, Qian W, Wang Z et al (2010) Prevalent positive epistasis in E. coli and S. cerevisiae metabolic networks. Nat Genet 42:272–276. https://doi.org/10.1038/ng.524
Herschlag D (1995) RNA chaperones and the RNA folding problem. J Biol Chem 270:20871–20874
Herschlag D, Khosla M, Tsuchihashi Z, Karpel RL (1994) An RNA chaperone activity of non-specific RNA binding proteins in hammerhead ribozyme catalysis. EMBO J 13:2913
Hunziker M, Barandun J, Petfalski E et al (2016) UtpA and UtpB chaperone nascent pre-ribosomal RNA and U3 snoRNA to initiate eukaryotic ribosome assembly. Nat Commun 7:12090. https://doi.org/10.1038/ncomms12090
Jarosz DF, Lindquist S (2010) Hsp90 and environmental stress transform the adaptive value of natural genetic variation. Science 330:1820–1824. https://doi.org/10.1126/science.1195487
Jiménez JI, Xulvi-Brunet R, Campbell GW et al (2013) Comprehensive experimental fitness landscape and evolutionary network for small RNA. Proc Natl Acad Sci 110:14984–14989. https://doi.org/10.1073/pnas.1307604110
Kobori S, Yokobayashi Y (2016) High-throughput mutational analysis of a twister ribozyme. Angew Chem Int Ed 55:10354–10357. https://doi.org/10.1002/anie.201605470
Kouyos RD, Silander OK, Bonhoeffer S (2007) Epistasis between deleterious mutations and the evolution of recombination. Trends Ecol Evol 22:308–315
Kun A, Santos M, Szathmary E (2005) Real ribozymes suggest a relaxed error threshold. Nat Genet 37:1008–1011. https://doi.org/10.1038/ng1621
Lehman N (2003) A case for the extreme antiquity of recombination. J Mol Evol 56:770–777. https://doi.org/10.1007/s00239-003-2454-1
Li C, Qian W, Maclean CJ, Zhang J (2016) The fitness landscape of a tRNA gene. Science 352:837–840. https://doi.org/10.1126/science.aae0568
Maraia RJ, Arimbasseri AG (2017) Factors that shape eukaryotic tRNAomes: processing, modification and anticodon–codon use. Biomolecules 7:26. https://doi.org/10.3390/biom7010026
Meyers LA, Lee JF, Cowperthwaite M, Ellington AD (2004) The Robustness of naturally and artificially selected nucleic acid secondary structures. J Mol Evol 58:681–691. https://doi.org/10.1007/s00239-004-2590-2
Ostman B, Hintze A, Adami C (2012) Impact of epistasis and pleiotropy on evolutionary adaptation. Proc Biol Sci 279:247–256. https://doi.org/10.1098/rspb.2011.0870
Pesce D, Lehman N, de Visser JAGM (2016) Sex in a test tube: testing the benefits of in vitro recombination. Philos Trans R Soc Lond B Biol Sci. https://doi.org/10.1098/rstb.2015.0529
Puchta O, Cseke B, Czaja H et al (2016) Network of epistatic interactions within a yeast snoRNA. Science 352:840–844. https://doi.org/10.1126/science.aaf0965
Queitsch C, Sangster TA, Lindquist S (2002) Hsp90 as a capacitor of phenotypic variation. Nature 417:618–624. https://doi.org/10.1038/nature749
Reinhold-Hurek B, Shub DA (1992) Self-splicing introns in tRNA genes of widely divergent bacteria. Nature 357:173–176. https://doi.org/10.1038/357173a0
Roth A, Weinberg Z, Chen AGY et al (2014) A widespread self-cleaving ribozyme class is revealed by bioinformatics. Nat Chem Biol 10:56–60. https://doi.org/10.1038/nchembio.1386
Rudan M, Schneider D, Warnecke T, Krisko A (2015) RNA chaperones buffer deleterious mutations in E. coli. eLife. https://doi.org/10.7554/eLife.04745
Russell R (2008) RNA misfolding and the action of chaperones. Front Biosci J Virtual Libr 13:1–20
Rutherford SL, Lindquist S (1998) Hsp90 as a capacitor for morphological evolution. Nature 396:336–342. https://doi.org/10.1038/24550
Sailer ZR, Harms MJ (2017) Detecting high-order epistasis in nonlinear genotype-phenotype maps. Genetics 205:1079–1088. https://doi.org/10.1534/genetics.116.195214
Sanjuán R (2010) Mutational fitness effects in RNA and single-stranded DNA viruses: common patterns revealed by site-directed mutagenesis studies. Philos Trans R Soc Lond B Biol Sci 365:1975–1982. https://doi.org/10.1098/rstb.2010.0063
Sanjuán R, Moya A, Elena SF (2004) The distribution of fitness effects caused by single-nucleotide substitutions in an RNA virus. Proc Natl Acad Sci USA 101:8396–8401. https://doi.org/10.1073/pnas.0400146101
Sinan S, Yuan X, Russell R (2011) The Azoarcus group I intron ribozyme misfolds and is accelerated for refolding by ATP-dependent RNA chaperone proteins. J Biol Chem 286:37304–37312
Soltanieh S, Osheim YN, Spasov K et al (2015) DEAD-box RNA helicase Dbp4 is required for small-subunit processome formation and function. Mol Cell Biol 35:816. https://doi.org/10.1128/MCB.01348-14
Soskine M, Tawfik DS (2010) Mutational effects and the evolution of new protein functions. Nat Rev Genet 11:572–582. https://doi.org/10.1038/nrg2808
Vaidya N, Manapat ML, Chen IA et al (2012) Spontaneous network formation among cooperative RNA replicators. Nature 491:72–77. https://doi.org/10.1038/nature11549
van Nimwegen E, Crutchfield JP, Huynen M (1999) Neutral evolution of mutational robustness. Proc Natl Acad Sci USA 96:9716–9720
Wagner A (2005) Robustness and evolvability in living systems. Princton University Press, Princeton
Wagner A (2011) The origins of evolutionary innovations: a theory of transformative change in living systems. OUP, Oxford
Weinreich DM, Watson RA, Chao L (2005) Perspective: Sign epistasis and genetic constraint on evolutionary trajectories. Evolution 59:1165–1174
Weinreich DM, Lan Y, Wylie CS, Heckendorn RB (2013) Should evolutionary geneticists worry about higher-order epistasis? Curr Opin Genet Dev 23:700–707. https://doi.org/10.1016/j.gde.2013.10.007
Weissman DB, Desai MM, Fisher DS, Feldman MW (2009) The rate at which asexual populations cross fitness valleys. Theor Popul Biol 75:286–300. https://doi.org/10.1016/j.tpb.2009.02.006
Whitlock MC, Phillips PC, Moore FB-G, Tonsor SJ (1995) Multiple fitness peaks and epistasis. Annu Rev Ecol Syst 26:601–629. https://doi.org/10.1146/annurev.es.26.110195.003125
Wilke CO, Adami C (2001) Interaction between directional epistasis and average mutational effects. Proc Biol Sci 268:1469–1474. https://doi.org/10.1098/rspb.2001.1690
Wilke CO, Lenski RE, Adami C (2003) Compensatory mutations cause excess of antagonistic epistasis in RNA secondary structure folding. BMC Evol Biol 3:3
Wylie CS, Shakhnovich EI (2011) A biophysical protein folding model accounts for most mutational fitness effects in viruses. Proc Natl Acad Sci 108:9916–9921. https://doi.org/10.1073/pnas.1017572108
Acknowledgements
We would like to thank J. Zhang, G. Kudla, and Y. Yokobayashi and the members of their labs for kindly granting access to the high-throughput sequencing data used in this project. This study was supported by Boise State University (Biomolecular Sciences Graduate Programs), University of California, Los Angeles (Department of Ecology and Evolutionary Biology), National Science Foundation Directorate for Biological Sciences (Grant No. MCB-1413664), National Science Foundation Office of Integrative Activities (Grant No. OIA-1738865), National Aeronautics and Space Administration (Grant No. 80NSSC17K0738), Idaho State University (Fall 2016 MRCF Seed Grant).
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Bendixsen, D.P., Østman, B. & Hayden, E.J. Negative Epistasis in Experimental RNA Fitness Landscapes. J Mol Evol 85, 159–168 (2017). https://doi.org/10.1007/s00239-017-9817-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00239-017-9817-5

