search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060
EISSN: 1678-8060
Vol. 101, No. s1, 2006, pp. 247-251
Bioline Code: oc06196
Full paper language: English
Document type: Research Article
Document available free of charge

Memórias do Instituto Oswaldo Cruz, Vol. 101, No. s1, 2006, pp. 247-251

 en Biomphalaria tenagophila check for this species in other resources : dynamics of populations of resistant and susceptible strains to Schistosoma mansoni check for this species in other resources , with or without pressure of the parasite
Florence Mara Rosa; Ana Lúcia Brunialti Godard; Deborah Negräo-Correa; Horácio Antonio Rodrigues; Omar dos Santos Carvalho; Roberta Lima Caldeira; Horácio Manoel Santana Teles Engels Maciel; Liana Konovaloff Jannotti-Passos & Paulo Marcos Zech Coelho

Abstract

Resistant (Taim, RS) and susceptible albino (Joinville, SC) Biomphalaria tenagophila check for this species in other resources populations were kept together, at different proportions, throughout a 18-month-period. Some of the snail groups were submitted to Schistosoma mansoni check for this species in other resources infection. The targets of this study were (a) to analyze the populational dynamics among resistant and susceptible individuals to S. mansoni ; (b) to study the resistance phenotype in descendants of cross-breeding; (c) to observe whether the parasite could exert any kind of selection in those snail populations. Throughout the experiment it could be observed that the susceptible B. tenagophila strain (Joinville) underwent a selective pressure of the parasite that was negative, since the individuals showed a high mortality rate. Although B. tenagophila (Taim) population presented a higher mortality rate without pressure of the parasite, this event was compensated by a reproductive capacity. B. tenagophila Taim was more fecund than B. tenagophila Joinville and was able to transmit the resistance character to their descendants. F1 generation obtained by cross-breeding between resistant and susceptible lineages was completely resistant to S. mansoni infection, irrespective of the Taim proportion. Moreover, less than 5% of F2 progeny were susceptible to S. mansoni infection.

Keywords
Biomphalaria tenagophila - dynamics of populations - Schistosoma mansoni - resistant and susceptible strains

 
© Copyright 2006 - Instituto Oswaldo Cruz - Fiocruz
Alternative site location: http://memorias.ioc.fiocruz.br

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2017, Site last up-dated on 05-Dec-2017.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil