ORIGINAL PAPER Variations in local adaptation of allopatric Fasciola hepatica to French Galba truncatula in relation to parasite origin Y. Dar & M. Lounnas & F. F. Djuikwo Teukeng & R. Mouzet & B. Courtioux & S. Hurtrez-Boussès & P. Vignoles & G. Dreyfuss & D. Rondelaud Received: 14 March 2013 / Accepted: 4 April 2013 / Published online: 21 April 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Two French populations of Galba truncatula were subjected to experimental infections with Egyptian and French isolates of Fasciola sp. miracidia, originating from cattle and sheep, to compare characteristics of snail infections in allopatric and sympatric groups. All sampled Egyptian isolates were identified as Fasciola hepatica using microsatellite markers. Compared to snails infected with French miracidia, snail survival at day 30 post-exposure was significantly greater in the Egyptian groups, while prevalence of infection was significantly lower (in an Egyp- tian group infected with cattle-derived miracidia) or did not show any significant differences in the other three cases. The total number of metacercariae was significantly higher in the four Egyptian groups. However, snail population and the mammalian origin of F . hepatica had also a significant effect on this parameter. The dissection of snail cadavers showed a significantly higher number of free rediae in the Egyptian groups, even if snail population also had a signif- icant effect on the redial burden. Both Egyptian isolates of F . hepatica could easily develop in French snails, causing a low mortality in snails and inducing a metacercarial produc- tion higher than that noted in sympatric infections. Howev- er, the mammalian origin of F . hepatica eggs and the quality of snail populations as intermediate hosts had to be taken into account for studying local adaptation in reason of their effects on this process. Introduction Since dispersal of digenean parasites is generally expected to be higher than dispersion of their molluscan intermediate hosts, theory predicts local host –parasite adaptation. Digeneans perform better on their local (sympatric) snail hosts than on foreign (allopatric) hosts (Ebert and Lorenzi 1994; Gandon 1998; Lively and Dybdahl 2000). In the model Fasciola hepatica/Galba truncatula, this interaction is characterized by a high prevalence of infection, a low mortality of infected snails during the prepatent period and a high cercarial production. These features have been reported in the laboratory (Boray 1966, 1969) and the field (Abrous et al. 1999, 2000, for example, in central France). However, there is an important interpopulation variability in the sus- ceptibility of G. truncatula to F . hepatica (Vignoles et al. 2002). Experiments conducted by Meunier (2002) showed that such differences have a genetic basis. Interestingly, some French populations of snails showed moderate or low susceptibility to local isolates of F . hepatica. Moreover, a significantly higher cercarial production of F . hepatica was noted in three French populations of snails highly susceptible to local parasites when experimentally infected with Spanish (Gasnier et al. 2000) or Moroccan (Goumghar et al. 2001) miracidia of this digenean. Compared to cercarial production of F . hepatica noted in sympatric combinations, this increase in allopatric combinations was 5.6 times (a single Y. Dar Department of Zoology, Faculty of Science, University of Tanta, Tanta, Egypt M. Lounnas : S. Hurtrez-Boussès MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution, Contrôle), UMR (UM 1-UM 2-CNRS 5290-IRD 224), IRD, B.P. 64501, 34394 Montpellier Cedex 5, France F. F. Djuikwo Teukeng Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé, B.P. 812, Yaoundé, Cameroon F. F. Djuikwo Teukeng : R. Mouzet : B. Courtioux : P. Vignoles : G. Dreyfuss (*) : D. Rondelaud INSERM U 1094, Faculties of Medicine and Pharmacy, 2, rue du Docteur Raymond Marcland, 87025 Limoges Cedex, France e-mail: gilles.dreyfuss@unilim.fr Parasitol Res (2013) 112:2543–2549 DOI 10.1007/s00436-013-3421-4