Mutational robustness


Mutational robustness

Mutational robustness describes the extent to which an organism’s phenotype remains constant in spite of mutation.[1] Natural selection can directly induce the evolution of mutational robustness only when mutation rates are high and population sizes are large.[2] The conditions under which selection could act to directly increase mutational robustness are extremely restrictive, and for this reason, such selection is thought to be limited to only a few viruses[3] and microbes[4] having large population sizes and high mutation rates. However, mutational robustness may evolve as a byproduct of natural selection for robustness to environmental perturbations.[5][6][7][8][9][10]

Mutational robustness is thought to be one driver for theoretical viral quasispecies formation.

Robustness and evolvability

Mutational Robustness appears to have a negative impact on evolvability because it reduces the mutational accessibility of distinct heritable phenotypes for a single genotype and reduces selective differences within a genetically diverse population.[11] Counter intuitively however, it has been hypothesized that phenotypic robustness towards mutations may actually increase the pace of heritable phenotypic adaptation when viewed over longer periods of time.[12][13][14][15][16][17][11][18] The hypothesis put forth is that connected networks of fitness neutral genotypes result in mutational robustness and reduced accessibility of heritable phenotypes over short timescales. On the other hand over longer periods of time, genetic drift combined with neutral/buffered mutations can provide mutational access to a greater number of distinct heritable phenotypes that are reached from different points of the genetic neutral network. This hypothesis is supported by simulations of biological systems.[13][14][15][16][17][11][18] and appears consistent with the available data on biomolecular evolution[14][19] Simulations have indicated that positive relationships between mutational robustness and evolvability can be facilitated by degeneracy within biological systems.[18]

See also

References

  1. ^ Wagner (2005). Robustness and evolvability in living systems. 
  2. ^ van Nimwegen E.,Crutchfield J. P., Huynen M. (1999). "Neutral evolution of mutational robustness". PNAS 96 (17): 9716–9720. 
  3. ^ Montville R, Froissart R, Remold SK, Tenaillon O, Turner PE (2005). "Evolution of mutational robustness in an RNA virus". PLoS Biology 3 (11): 1939–1945. 
  4. ^ Masel J, Maughan H (2007). "Mutations Leading to Loss of Sporulation Ability in Bacillus subtilis Are Sufficiently Frequent to Favor Genetic Canalization". Genetics 175: 453–457. doi:10.1534/genetics.106.065201. 
  5. ^ Meiklejohn CD, Hartl DL (2002). "A single mode of canalization". Trends in Ecology & Evolution 17: e9035. 
  6. ^ Ancel LW, Fontana W (2000). "Plasticity, evolvability, and modularity in RNA". Journal of Experimental Zoology 288 (3): 242–283. doi:10.1002/1097-010X(20001015)288:3<242::AID-JEZ5>3.0.CO;2-O. PMID 11069142. 
  7. ^ Szöllősi GJ, Derényi I (2009). "Congruent Evolution of Genetic and Environmental Robustness in Micro-RNA". Molecular Biology & Evolution 26 (4): 867–874. doi:10.1093/molbev/msp008. PMID 19168567. 
  8. ^ Wagner GP, Booth G Bagheri-Chaichian H (1997). "A population genetic theory of canalization". Evolution 51 (2): 329–347. doi:10.2307/2411105. JSTOR 2411105. 
  9. ^ Lehner B (2010). "Genes Confer Similar Robustness to Environmental, Stochastic, and Genetic Perturbations in Yeast". PLoS ONE 5 (2): 468–473. doi:10.1371/journal.pone.0009035. PMC 2815791. PMID 20140261. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0009035. 
  10. ^ Masel J Siegal ML (2009). "Robustness: mechanisms and consequences". Trends in Genetics 25 (9): 395–403. doi:10.1016/j.tig.2009.07.005. PMC 2770586. PMID 19717203. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2770586. 
  11. ^ a b c Wagner (2008). "Robustness and evolvability: a paradox resolved". Proceedings of the Royal Society of London, Series B: Biological Sciences 275: 91–100. 
  12. ^ Masel J, Trotter MV (2010). "Robustness and evolvability". Trends in Genetics 26 (9): 406–414. doi:10.1016/j.tig.2010.06.002. PMID 20598394. 
  13. ^ a b Aldana et al. (2007). "Robustness and evolvability in genetic regulatory networks". Journal of Theoretical Biology 245 (3): 433–448. 
  14. ^ a b c Bloom et al. (2006). "Protein stability promotes evolvability". Proceedings of the National Academy of Sciences 103 (15): 5869. 
  15. ^ a b Babajide et al. (1997). "Neutral networks in protein space: A computational study based on knowledge-based potentials of mean force". Folding and Design 2 (5): 261–269. 
  16. ^ a b van Nimwegen and Crutchfield (2000). "Metastable evolutionary dynamics: Crossing fitness barriers or escaping via neutral paths?". Bulletin of Mathematical Biology 62 (5): 799–848. 
  17. ^ a b Ciliberti et al. (2007). "Innovation and robustness in complex regulatory gene networks". Proceedings of the National Academy of Sciences, USA 104 (34): 13591–13596. 
  18. ^ a b c Whitacre and Bender (2010). "Degeneracy: a design principle for achieving robustness and evolvability". Journal of Theoretical Biology 263 (1): 143–153. doi:10.1016/j.jtbi.2009.11.008. PMID 19925810. 
  19. ^ Andreas Wagner (2008). "Neutralism and selectionism: a network-based reconciliation". Nature Reviews Genetics 9 (12): 965–974. doi:10.1038/nrg2473. PMID 18957969.