Spatially induced nestedness in a neutral model of phage-bacteria networks

Valverde, Sergi; Elena, Santiago F.; Solé Vicente, Ricard, 1962-

doi:http://dx.doi.org/10.1093/ve/vex021

Spatially induced nestedness in a neutral model of phage-bacteria networks

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Citació

Valverde S, Elena SF, Solé R. Spatially induced nestedness in a neutral model of phage-bacteria networks. Virus Evolution. 2017 Jul;3(2):vex021. DOI: 10.1093/ve/vex021

Resum

Ecological networks, both displaying mutualistic or antagonistic interactions, seem to share common structural traits: the presence of nestedness and modularity. A variety of model approaches and hypothesis have been formulated concerning the significance and implications of these properties. In phage-bacteria bipartite infection networks, nestedness seems to be the rule in many different contexts. Modeling the coevolution of a diverse virus–host ensemble is a difficult task, given the dimensionality and multi parametric nature of a standard continuous approximation. Here, we take a different approach, by using a neutral, toy model of host–phage interactions on a spatial lattice. Each individual is represented by a bit string (a digital genome) but all strings in each class (i.e. hosts or phages) share the same sets of parameters. A matching allele model of phage-virus recognition rule is enough to generate a complex, diverse ecosystem with heterogeneous patterns of interaction and nestedness, provided that interactions take place under a spatially constrained setting. It is found that nestedness seems to be an emergent property of the co-evolutionary dynamics. Our results indicate that the enhanced diversity resulting from localized interactions strongly promotes the presence of nested infection matrices.