title: An example of molecular co-evolution: reactive oxygen species (ROS) and ROS scavenger levels in Schistosoma mansoni/Biomphalaria glabrata interactions.
abstract: The co-evolution between hosts and parasites involves huge reciprocal selective pressures on both protagonists. However, relatively few reports have evaluated the impact of these reciprocal pressures on the molecular determinants at the core of the relevant interaction, such as the factors influencing parasitic virulence and host resistance. Here, we address this question in a host-parasite model that allows co-evolution to be monitored in the field: the interaction between the mollusc, Biomphalaria glabrata, and its trematode parasite, Schistosoma mansoni. Reactive oxygen species (ROS) produced by the haemocytes of B. glabrata are known to play a crucial role in killing S. mansoni. Therefore, the parasite must defend itself against oxidative damage caused by ROS using ROS scavengers in order to survive. In this context, ROS and ROS scavengers are involved in a co-evolutionary arms race, and their respective production levels by sympatric host and parasite could be expected to be closely related. Here, we test this hypothesis by comparing host oxidant and parasite antioxidant capabilities between two S. mansoni/B. glabrata populations that have co-evolved independently. As expected, our findings show a clear link between the oxidant and antioxidant levels, presumably resulting from sympatric co-evolution. We believe this work provides the first supporting evidence of the Red Queen Hypothesis of reciprocal evolution for functional traits at the field-level in a model involving a host and a eukaryotic parasite.
authors.affiliation: Parasitologie Fonctionnelle et Evolutive, UMR 5244, CNRS Université de Perpignan, 52 Ave Paul Alduy, 66860 Perpignan Cedex, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Moné
authors.forename: Anne-Cécile
authors.initials: AC
authors.lastname: Ribou
authors.forename: Céline
authors.initials: C
authors.lastname: Cosseau
authors.forename: David
authors.initials: D
authors.lastname: Duval
authors.forename: André
authors.initials: A
authors.lastname: Théron
authors.forename: Guillaume
authors.initials: G
authors.lastname: Mitta
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gourbal
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001700:Biomphalaria / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology*; D016166:Free Radical Scavengers / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012550:Schistosoma mansoni / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species