Changes in Population Dynamics in Mutualistic versus Pathogenic Viruses

Abstract

Although generally regarded as pathogens, viruses can also be mutualists. A number of examples of extreme mutualism (i.e., symbiogenesis) have been well studied. Other examples of mutualism are less common, but this is likely because viruses have rarely been thought of as having any beneficial effects on their hosts. The effect of mutualism on the population dynamics of viruses is a topic that has not been addressed experimentally. However, the potential for understanding mutualism and how a virus might become a mutualist may be elucidated by understanding these dynamics.

Alphaherpesvirus axon-to-cell spread involves limited virion transmission

“…Studies of plant RNA viruses generally report small effective population sizes during transmission, whereas studies with one plant DNA virus reported a large population of virions during spread in single plant (21)(22)(23). The transmission of HIV between T cells involves transmission of a large number of virions across a virological synapse (2,24).…”

Infectious agents and inflammation in donated hearts and dilated cardiomyopathies related to cardiovascular diseases, Chagas' heart disease, primary and secondary dilated cardiomyopathies

“…However, an additional hypothesis could be postulated specifically for Chagas' heart disease. In theory, co-infection could modulate the complex interactions between parasite and host, and in addition, any infectious agent by itself might contribute to myocardial dysfunction [39][40][41]. Considering our findings, we would like to speculate that the increase in non T. cruzi microorganisms in the myocardial tissue could lead to an imbalance triggering worsening or full development of chagasic DCM.…”

Parasitoid Wasps and Their Venoms

“…PDVs are an endogenous and integral part of endoparasitoid genome (Belle et al 2002) and are produced in the ovarian calyx of the wasp (Wyler and Lanzrein 2003). PDVs can deliver non-viral wasp genes into hosts to perform immune suppressive functions (Webb 1998;Roossinck 2011;Drezen et al 2014). PDVs became incorporated into certain groups of braconid and ichneumonid genomes in two independent events (Webb 1998), with braconid PDVs or bracoviruses originating~74 mya (Whitfield 2002).…”