Schistosoma mansoni: Electrophoretic characterization of strains selected for different levels of infectivity to snails

Madeleine Fletcher, Philip T. LoVerde, Charles S. Richards

Research output: Contribution to journalArticle

23 Scopus citations


Individual adult Schistosoma mansoni from strains selected for high or low infectivity to specific strains of the snail intermediate host, Biomphalaria glabrata, were subjected to enzyme electrophoresis on starch gels. Fourteen enzyme systems were analyzed in an attempt to find electrophoretic markers associated with genes for infectivity to snails. The S. mansoni strains were selected from different isolates from Puerto Rico in several strains of B. glabrata. Of an estimated 18 loci, 3 were polymorphic and the remainder monomorphic. For 1 of the 3 polymorphic enzyme loci, lactate dehydrogenase (Ldh, EC, phenotype frequencies were correlated with infectivity to snails. In schistosome strains of low infectivity, frequencies of the Ldh-N phenotype ranged between 0.56 and 0.69, while in strains of high infectivity, Ldh-N frequencies were typically 0.91 to 1.00. Whether the correlation is accidental or due to some form of association, such as chromosomal linkage, between the locus responsible for variation in lactate dehydrogenase and a gene for infectivity to snails remains to be determined.

Original languageEnglish (US)
Pages (from-to)362-370
Number of pages9
JournalExperimental Parasitology
Issue number3
StatePublished - Dec 1981



  • Biomphalaria glabrata
  • Blood fluke
  • Chromosomal linkage
  • Differentiation, intraspecific
  • Enzyme electrophoresis
  • Genetics
  • Infectivity
  • Lactate dehydrogenase (EC
  • Schistosoma mansoni
  • Trematode
  • snail

ASJC Scopus subject areas

  • Parasitology
  • Immunology
  • Infectious Diseases

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