The Fittest versus the Flattest: Experimental Confirmation of the Quasispecies Effect with Subviral Pathogens

PLoS Pathogens

Ricard V Solé¹  José-Antonio Darós²  Francisco M Codoñer²  Santiago F Elena³ 

[1] Complex Systems Laboratory, Institució Catalana de Recerca i Estudis Avançats-Universitat Pompeu Fabra, Barcelona, Spain;Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas–Universitat Politècnica de València, València, Spain;Santa Fe Institute, Santa Fe, New Mexico, United States of America

关键词: Viroids;    Ultraviolet C;    Population genetics;    Genetic polymorphism;    Haplotypes;    Plant physiology;    Species diversity;    Viral replication;   

DOI  :  10.1371/journal.ppat.0020136

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The “survival of the fittest” is the paradigm of Darwinian evolution in which the best-adapted replicators are favored by natural selection. However, at high mutation rates, the fittest organisms are not necessarily the fastest replicators but rather are those that show the greatest robustness against deleterious mutational effects, even at the cost of a low replication rate. This scenario, dubbed the “survival of the flattest”, has so far only been shown to operate in digital organisms. We show that “survival of the flattest” can also occur in biological entities by analyzing the outcome of competition between two viroid species coinfecting the same plant. Under optimal growth conditions, a viroid species characterized by fast population growth and genetic homogeneity outcompeted a viroid species with slow population growth and a high degree of variation. In contrast, the slow-growth species was able to outcompete the fast species when the mutation rate was increased. These experimental results were supported by an in silico model of competing viroid quasispecies.

【 授权许可】

CC BY