schistosome-induced portacaval haemodynamic changes in rattus rattus are associated with translocation of adult worms to the lungs.the presence of naturally portacaval shunts has been investigated in the vasculature of normal and schistosoma mansoni-infected rattus rattus. using the technique of injecting polystyrene microspheres in the superior mesenteric vein, we demonstrated that the presence of adult schistosomes in the lungs of r. rattus was not due to an innate anomaly of the rat vasculature but resulted from the formation of portacaval shunts during infection. in rats harbouring a bisexual infection, microspheres wer ...19989550217
parasite (schistosoma mansoni) and host (biomphalaria glabrata) genetic diversity: population structure in a fragmented landscape.random amplified polymorphic dna (rapd) markers were used to quantify genetic diversity within and between 5 populations of schistosoma mansoni within its definitive host (rattus rattus) and the 5 corresponding populations of the snail intermediate host (biomphalaria glabrata) from a limited endemic area of murine schistosomiasis on the island of guadeloupe. analysis of molecular variance (amova) and canonical correspondence analysis (cca) were used to test the significance of genetic differenti ...200111393828
genetic diversity of schistosoma mansoni within and among individual hosts (rattus rattus): infrapopulation differentiation at microspatial scale.the distribution of genetic diversity in a local population of the trematode schistosoma mansoni was determined within and between individual wild rats at a microspatial geographic scale of a standing water transmission site. using rapd markers, molecular variance and canonical correspondence analysis were performed to test the significance of genetic differentiation between infrapopulations. of total gene diversity, 8 and 11% was partitioned between hosts trapped at few metres distance from eac ...200111730788
sex-specific genetic structure in schistosoma mansoni: evolutionary and epidemiological implications.we studied the population genetic structure of 360 and 1247 adult schistosoma mansoni using seven microsatellite and seven random amplified polymorphic dna (rapd) markers, respectively. parasites were collected from their natural definitive host rattus rattus in guadeloupe (west indies). we found a sex-specific genetic structure, a pattern never before reported in a parasitic organism. male genotypes were more randomly distributed among rats than female genotypes. this interpretation was consist ...200212074730
molecular ecology of schistosoma mansoni transmission inferred from the genetic composition of larval and adult infrapopulations within intermediate and definitive hosts.we investigated the genotypic composition of the digenetic parasite schistosoma mansoni for its adult stages within the definitive host (the wild rat, rattus rattus) and for the larval stages within the intermediate host (the snail, biomphalaria glabrata) both collected at the same transmission site. our analyses are based upon the recognition and distribution of 200 different multilocus genotypes generated by rapd markers. while intramolluscan larval infrapopulations are characterized by a low ...200415552402
dispersal in a parasitic worm and its two hosts: consequence for local adaptation.characterizing host and parasite population genetic structure and estimating gene flow among populations is essential for understanding coevolutionary interactions between hosts and parasites. we examined the population genetic structure of the trematode schistosoma mansoni and its two host species (the definitive host rattus rattus and the intermediate host biomphalaria glabrata) using microsatellite markers. parasites were sampled from rats. the study was conducted in five sites of the guadelo ...200515807416
f-statistics under alternation of sexual and asexual reproduction: a model and data from schistosomes (platyhelminth parasites).accurate inferences on population genetics data require a sound underlying theoretical null model. nearly nothing is known about the gene dynamics of organisms with complex life cycles precluding any biological interpretation of population genetics parameters. in this article, we used an infinite island model to derive the expectations of those parameters for the life cycle of a dioecious organism obligatorily alternating sexual and asexual reproductions as it is the case for schistosomes (plath ...200515813776
island colonization and founder effects: the invasion of the guadeloupe islands by ship rats (rattus rattus).the stepwise colonization of islands within an archipelago is typically punctuated by successive founder effects, with each newly founded population being a subsample of the gene pool of the source island. thus, the genetic signature of successive bottlenecks should be detected when analysing the genetic structure between islands of an archipelago. to test this prediction, we investigated introduced ship rat populations, rattus rattus (linnaeus, 1758), in the guadeloupe archipelago. three differ ...200516101763
Displaying items 1 - 8 of 8