Biomphalaria tenagophila: dominant character of the resistance to Schistosoma mansoni in descendants of crossbreedings between resistant (Taim, RS) and susceptible (Joinville, SC) strains

• Main Authors: Florence Mara Rosa, Ana Lúcia Brunialti Godard, Vasco Azevedo, Paulo Marcos Zech Coelho
• Format: Article
• Language: English
• Published: Instituto Oswaldo Cruz, Ministério da Saúde 2005-02-01
• Series: Memórias do Instituto Oswaldo Cruz.
• Subjects: Biomphalaria tenagophila; dominant resistance character; Schistosoma mansoni; crossbreedings
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762005000100004

The aim of the present work was to study parasitological, molecular, and genetic aspects in descendants of crossbreedings between a totally resistant Biomphalaria tenagophila strain (Taim, RS) and another one highly susceptible (Joinville, SC) to Schistosoma mansoni. Descendants F1 and F2 were submitted to S. mansoni infection (LE strain). The susceptibility rates for individuals from Group F1 were 0 to 0.6%, and from Group F2 was 7.2%. The susceptible individuals from Group F2 discharged a lower number of cercariae, when compared with the susceptible parental group, and in 2 out of 9 positive snails the cercarial elimination was discontinued. In order to identify genetic markers associated with resistance the genotype of parental snails and their offspring F1 and F2 were analyzed by means of the randomly amplified polymorphic DNA method. Nevertheless, it was not possible to detect any marker associated to resistance, but the results showed that in the mentioned species the resistance character is determined by two dominant genes.