Evolution of Thermotolerance and Robustness in Viruses

Viruses can rapidly degrade in stressful environments, such as exposure to heat shock (elevated temperature). We examine the evolutionary genetics of virus adaptation in stressful environments, to determine the mutations responsible for increased particle stability to tolerate temperature changes (thermotolerance). More generally, these studies test ecological and evolutionary theory on population persistence vs. extinction, when environments change deterministically and stochastically. Robustness is the ability to maintain phenotypic performance (fitness) despite the introduction of genetic changes to the genome (mutational robustness), or changes in the environment (environmental robustness). We study how robustness evolves in viruses, especially in RNA viruses where mutational robustness may be particularly important in the face of elevated mutation rates. Our results show that evolution of environmental robustness (e.g., thermotolerance) is sometimes contingent on evolution of mutational robustness – and vice versa – in virus populations.

Examples:

• Wieczynski, D.J., P.E. Turner, and D.A. Vasseur. 2018. Temporally autocorrelated environmental fluctuations inhibit the evolution of stress tolerance. American Naturalist (In press)

• Wasik, B.R., A. Bhushan, C.B. Ogbunugafor, and P.E. Turner. 2014. Delayed transmission selects for increased survival of vesicular stomatitis virus. Evolution 69(1):117-125. PMID: 25311513

• Ogbunugafor, C.B., B.W. Alto, T. Overton, A. Bhushan, N. Morales, and P.E. Turner. 2013. Evolution of increased survival in RNA viruses specialized on cancer-derived cells. American Naturalist 181(5):585-595. PMID: 23594543

• Alto, B., B. Wasik, N. Morales, and P.E. Turner. 2013. Stochastic temperatures impede RNA virus adaptation. Evolution 67:969-979. PMID: 23550749

• Ogbunugafor, C.B., R.C. McBride and P.E. Turner. 2009. Predicting virus evolution: the relationship between genetic robustness and evolvability of thermotolerance. Cold Spring Harbor Symposia on Quantitative Biology 74:109-118.

• McBride, R.C., C.B. Ogbunugafor, and P.E. Turner. 2008. Robustness promotes evolvability of thermotolerance in an RNA virus. BMC Evolutionary Biology 8:231.

• Dennehy, J.J., N.A. Friedenberg, Y.W. Yang, and P.E. Turner. 2007. Virus population extinction via ecological traps. Ecology Letters 10:230-240

• Montville, R., R. Froissart, S.K. Remold, O. Tenaillon, and P.E. Turner. 2005. Evolution of mutational robustness in RNA viruses. PLoS Biology 3:1939-1945. PMCID: PMC1456243.