Genetic complementation analysis of two independently isolated hycanthone-resistant strains of Schistosoma mansoni

The objective of this study is to determine whether various hycanthone resistant strains of schistosomes which have been independently isolated are all affected in the same gene. A strain obtained from a Brazilian patient was compared with a strain of Puerto Rican origin selected in the laboratory. If the mutation conferring resistance involved two different genes, one would expect that progeny of a cross between the two strains would show complementation, i.e. it would be sensitive to the drug. We have performed such a cross and obtained F1 hybrid worms which were essentially all resistant, thus suggesting that the mutation conferring resistance in the two strains involves the same gene.