title: Epigenetic origin of adaptive phenotypic variants in the human blood fluke Schistosoma mansoni.
abstract: BACKGROUND
  Adaptive evolution is not possible without the generation of phenotypic variants. The origin of these variations has been a central topic in evolutionary biology. Up to now, it was commonly accepted that standing genetic variation is the only cause of phenotypic variants. However, epigenetic information is emerging as a complementary source of heritable phenotypic variation that contributes to evolution. The relative importance of genetics and epigenetics in generating heritable phenotypic variation is nevertheless a matter of debate.
  
  
  RESULTS
  We used a host-parasite system to address this question. The human blood fluke Schistosoma mansoni can adapt rapidly to new intermediate snail hosts. The interaction between parasite and mollusk is characterized by a compatibility polymorphism illustrating the evolutionary dynamics in this system. The principal molecular marker for compatibility (infection success) is the expression pattern of a group of polymorphic mucins (SmPoMuc) in the parasite. We show here that chromatin structure changes as the SmPoMuc promoters are the cause for SmPoMuc transcription polymorphism leading to phenotypic novelty and increase in infection success, i.e., fitness.
  
  
  CONCLUSIONS
  We establish that epigenetic changes can be the major if not only cause of adaptive phenotypic variants in Schistosoma mansoni, suggesting that epimutations can provide material for adaptive evolution in the absence of genetic variation in other systems. In addition, our results indicate that epidrugs can be used to control parasite development but also parasite evolution.
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France ; UMR BDR, INRA, ENVA, Université Paris Saclay, 78350 Jouy en Josas, France.
authors.forename: Sara
authors.initials: S
authors.lastname: Fneich
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: André
authors.initials: A
authors.lastname: Théron
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Cosseau
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Rognon
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Aliaga
authors.affiliation: CNRS, UPR1142, Institut de Génétique Humain (IGH), 34396 Montpellier, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Buard
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: David
authors.initials: D
authors.lastname: Duval
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Arancibia
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Boissier
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France ; Technical University of Munich (TUM), Liesel-Beckmann-Str. 2, 85354 Freising, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Roquis
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Mitta
authors.affiliation: IHPE, Université de Perpignan Via Domitia (UPVD), 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France ; CNRS, UMR 5244, Interactions Hôtes-Pathogènes-Environnements (IHPE), 66860 Perpignan, France.
authors.forename: Christoph
authors.initials: C
authors.lastname: Grunau
keywords: Adaptive evolution; Compatibility polymorphism; Epigenetics; Schistosoma mansoni