title: Follow-up of the genetic diversity and snail infectivity of a Schistosoma mansoni strain from field to laboratory.
abstract: Schistosoma mansoni is an endoparasite causing a serious human disease called schistosomiasis. The quantification of parasite genetic diversity is an essential component to understand schistosomiasis epidemiology and disease transmission patterns but some studies on parasite genetic diversity are performed using parasite laboratory strains. However, a potential discrepancy in level of genetic variation between field populations and laboratory strains may have various implications in our deductions. In this study, 246 adult worms were analysed on 15 microsatellite markers to investigate variation of genetic diversity between a founder field isolate and the nine successive laboratory generations during three years of laboratory maintenance. In parallel, we measured a parasite life trait (snail infectivity) at each generation in order to test a potential link between inbreeding and snail infectivity. Our genetic analyses demonstrate a significant genetic differentiation between all parasite generations and a significant isolation by time associated with a decrease in neutral genetic diversity that is likely to be the result of successive bottleneck events. However, while snail infectivity decreases sharply between field isolate and the first laboratory generation, this parasite life trait does not evolve between other laboratory generations and appeared disconnected from this continuous neutral genetic diversity loss. We hypothesize that a sufficient level of compatibility polymorphism at a genomic level is maintained independently of an increase of inbreeding, ensuring the stability in the parasite life trait.
authors.affiliation: Laboratoire de Biologie et d'Ecologie Tropicale et Méditerranéenne, UMR 5244 CNRS-UPVD, Université de Perpignan, 52 Avenue Paul Alduy, 66860 Perpignan Cedex, France. nicolas.bech@univ-perp.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bech
authors.forename: Sophie
authors.initials: S
authors.lastname: Beltran
authors.forename: Julien
authors.initials: J
authors.lastname: Portela
authors.forename: Anne
authors.initials: A
authors.lastname: Rognon
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Allienne
authors.forename: Jérôme
authors.initials: J
authors.lastname: Boissier
authors.forename: André
authors.initials: A
authors.lastname: Théron
mesh_terms: D000818:Animals; D014644:Genetic Variation; D005838:Genotype; D012550:Schistosoma mansoni / Q000235:genetics* / Q000502:physiology*; D012908:Snails / Q000469:parasitology*