title: Continuous in vitro propagation and differentiation of cultures of the intramolluscan stages of the human parasite Schistosoma mansoni.
abstract: The metazoan parasitic blood flukes, Schistosoma spp., infect over 200 million people worldwide and cause extensive human morbidity and mortality. Research strategies for development of anti-schistosomal agents are impeded by the organism's complex molluscan-mammalian life cycle, which limits experimental approaches and availability of material. We derived long-term continuously proliferative cultures of Schistosoma mansoni sporocysts capable of generating cercariae in vitro. Cultured organisms retained the ability to parasitize the host, and they exhibited developmental regulation of candidate stage-specific genes in the host-free culture system. Evidence for expression of a reverse transcriptase also was found in the cultured organisms, pointing to this activity as a possible mechanistic contributor to the dynamic relationship between the parasite and its hosts. Continuous in vitro propagation of the asexual sporocyst stage allows isolation of clonally derived parasite populations and provides a means to study schistosomal molecular genetics, metabolism, and evasion of host defenses.
authors.affiliation: Department of Zoology, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Ivanchenko
authors.forename: J P
authors.initials: JP
authors.lastname: Lerner
authors.forename: R S
authors.initials: RS
authors.lastname: McCormick
authors.forename: A
authors.initials: A
authors.lastname: Toumadje
authors.forename: B
authors.initials: B
authors.lastname: Allen
authors.forename: K
authors.initials: K
authors.lastname: Fischer
authors.forename: O
authors.initials: O
authors.lastname: Hedstrom
authors.forename: A
authors.initials: A
authors.lastname: Helmrich
authors.forename: D W
authors.initials: DW
authors.lastname: Barnes
authors.forename: C J
authors.initials: CJ
authors.lastname: Bayne
mesh_terms: D000818:Animals; D046508:Culture Techniques / Q000379:methods*; D005786:Gene Expression Regulation; D006801:Humans; D008974:Mollusca / Q000469:parasitology; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D012550:Schistosoma mansoni / Q000166:cytology* / Q000235:genetics / Q000254:growth & development*
chemical_list: D012194:RNA-Directed DNA Polymerase