Lookup NU author(s): Dr Brian Ford
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Viruses readily mutate and gain the ability to infect novel hosts, but few data are available regarding the number of possible host range-expanding mutations allowing infection of any given novel host, and the fitness consequences of these mutations on original and novel hosts. To gain insight into the process of host range expansion, we isolated and sequenced 69 independent mutants of the dsRNA bacteriophage 6 able to infect the novel host, Pseudomonas pseudoalcaligenes. In total, we found at least 17 unique suites of mutations among these 69 mutants. We assayed fitness for 13 of 17 mutant genotypes on P. pseudoalcaligenes and the standard laboratory host, P. phaseolicola. Mutants exhibited significantly lower fitnesses on P. pseudoalcaligenes compared to P. phaseolicola. Furthermore, 12 of the 13 assayed mutants showed reduced fitness on P. phaseolicola compared to wildtype 6, confirming the prevalence of antagonistic pleiotropy during host range expansion. Further experiments revealed that the mechanistic basis of these fitness differences was likely variation in host attachment ability. In addition, using computational protein modeling, we show that host-range expanding mutations occurred in hotspots on the surface of the phage's host attachment protein opposite a putative hydrophobic anchoring domain.
Author(s): Ford BE, Sun B, Carpino J, Chapler ES, Ching J, Choi Y, Jhun K, Kim JD, Lallos GG, Morgenstern R, Singh S, Theja S, Dennehy JJ
Publication type: Article
Publication status: Published
Journal: PLoS ONE
Online publication date: 19/11/2014
Acceptance date: 15/10/2014
Date deposited: 20/03/2019
ISSN (electronic): 1932-6203
Publisher: Public Library of Science
PubMed id: 25409341
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