Genetic variability and identification of the intermediate snail hosts of Schistosoma mansoni

Studies based on shell or reproductive organ morphology and genetic considerations suggest extensive intraspecific variation in Biomphalaria snails. The high variability at the morphological and genetic levels, as well as the small size of some specimens and similarities between species complicate t...

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Bibliographic Details
Published in:Memórias do Instituto Oswaldo Cruz
Main Authors: Teofânia HDA Vidigal, Emmanuel Dias Neto, Linus Spatz, Diana N Nunes, Edina R Pires, Andrew JG Simpson, Omar S Carvalho
Format: Article in Journal/Newspaper
Language:English
Published: Instituto Oswaldo Cruz, Ministério da Saúde 1998
Subjects:
Biomphalaria
snails
genetic variability
identification
polymerase chain reaction
Arctic medicine. Tropical medicine
RC955-962
Microbiology
QR1-502
Arctic
Argentina
Uruguay
Online Access:https://doi.org/10.1590/S0074-02761998000700014
https://doaj.org/article/31c5a3b2e9fc410fa6dbc017d386b477
Description
Summary:Studies based on shell or reproductive organ morphology and genetic considerations suggest extensive intraspecific variation in Biomphalaria snails. The high variability at the morphological and genetic levels, as well as the small size of some specimens and similarities between species complicate the correct identification of these snails. Here we review our work using methods based on polymerase chain reaction (PCR) amplification for analysis of genetic variation and identification of Biomphalaria snails from Brazil, Argentina, Uruguay and Paraguay. Arbitrarily primed-PCR revealed that the genome of B. glabrata exihibits a remarkable degree of intraespecific polymorphism. Low stringency-PCR using primers for 18S rRNA permited the identification of B. glabrata, B. tenagophila and B. occidentalis. The study of individuals obtained from geographically distinct populations exhibits significant intraspecific DNA polymorphism, however specimens from the same species, exhibit some species specific LSPs. We also showed that PCR-restriction fragment of length polymorphism of the internal transcribed spacer region of Biomphalaria rDNA, using DdeI permits the differentiation of the three intermediate hosts of Schistosoma mansoni. The molecular biological techniques used in our studies are very useful for the generation of new knowledge concerning the systematics and population genetics of Biomphalaria snails.

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