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Updated: Mar 1, 2026
12:05
Mass Isolation and In Vitro Cultivation of Intramolluscan Stages of the Human Blood Fluke Schistosoma Mansoni
Published on: January 14, 2018
9.9K
SELECTION AND STRAIN SPECIFICITY OF COMPATIBILITY BETWEEN SNAIL INTERMEDIATE HOSTS AND THEIR PARASITIC SCHISTOSOMES
J P Webster1, M E J Woolhouse1
1Wellcome Trust Centre for the Epidemiology of Infectious Disease, Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, United Kingdom.
Summary
Host-parasite coevolution models often assume genetically based, strain-specific resistance. This study experimentally demonstrates heritable resistance in Biomphalaria glabrata snails to Schistosoma mansoni, supporting coevolutionary dynamics.
Area of Science:
- Evolutionary Biology
- Parasitology
- Genetics
Background:
- Host-parasite coevolution models frequently hypothesize genetically determined, parasite strain-specific host resistance.
- Experimental validation of these assumptions in animal-parasite systems remains limited.
- Biomphalaria glabrata snails are intermediate hosts for Schistosoma mansoni, with observed but unfixed resistance in natural populations.
Purpose of the Study:
- To experimentally test the heritability and specificity of genetic resistance in Biomphalaria glabrata to Schistosoma mansoni.
- To investigate potential genetic trade-offs in snail resistance across different parasite strains.
Main Methods:
- Artificial selection was applied to two Biomphalaria glabrata snail strains for resistance or susceptibility to two Schistosoma mansoni strains over three generations.
- Third-generation snails were challenged with either their selected parasite strain or a different strain to assess cross-resistance.
- Heritability of resistance and susceptibility (compatibility) was evaluated.
Main Results:
- Both resistance and susceptibility (compatibility) to Schistosoma mansoni were found to be heritable in the selected Biomphalaria glabrata strains.
- Compatibility to one Schistosoma mansoni strain did not correlate with compatibility to a different strain, indicating no observed genetic trade-off.
- The findings support strain-specific genetic interactions in the host-parasite system.
Conclusions:
- The genetic basis for resistance and susceptibility in Biomphalaria glabrata to Schistosoma mansoni is confirmed.
- The absence of cross-resistance suggests that host resistance mechanisms are specific to parasite strains, aligning with theoretical coevolutionary models.
- These results have significant implications for understanding host-parasite dynamics and coevolutionary theory.
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