The inheritance of susceptibility to infection with Schistosoma mansoni in Australorbis glabratus
| Autor: | Walter L. Newton |
|---|---|
| Rok vydání: | 1953 |
| Předmět: |
biology
Ecology Strain (biology) Immunology Zoology Aquatic animal Schistosomiasis General Medicine Snail biology.organism_classification medicine.disease Infectious Diseases biology.animal parasitic diseases medicine Helminths Parasite hosting Parasitology Schistosoma mansoni geographic locations Freshwater mollusc |
| Zdroj: | Experimental Parasitology. 2:242-257 |
| ISSN: | 0014-4894 |
| DOI: | 10.1016/0014-4894(53)90036-8 |
| Popis: | Studies were conducted to ascertain whether genetic factors were involved in the susceptibility difference between a Brazilian and a Puerto Rican strain of Australorbis glabratus to a Puerto Rican strain of Schistosoma mansoni . Since it was found that non-genetic factors such as the number of miracidia used for exposure and the size and age of the snails exerted some influence upon susceptibility and infection rate, a standard set of exposure conditions was used. Under these conditions 95% of the Puerto Rican snails were positive for cercariae after 30 to 32 days, whereas none of the Brazilian snails became infected. Crosses were made between members of the two snail strains, and the progeny therefrom were exposed to infection under the conditions mentioned above. Because A. glabratus can self- as well as cross-fertilize, a red mutant variety of the Brazilian strain which was recessive to the wild-type pigmented condition was used as a member of a pair to ascertain when crossing had occurred. F 1 progeny from some Brazilian parents which had crossed with Puerto Rican snails included susceptibles; F 1 's from other crosses did not. F 2 populations derived from selfed nonsusceptible F 1 's had infection rates which showed a continuous type of distribution from 3 to 58%. The red members of the F 2 populations showed a slightly, but significantly, higher infection rate than did the pigmented members. F 3 populations derived from nonsusceptible F 2 parents had infection rates varying from 0 to 82%. Particular infection rates were replicated in several of the populations. The findings demonstrated that susceptibility to S. mansoni infection in A. glabratus is a heritable character, and that several genetic factors are probably involved. The Puerto Rican and Brazilian strains of A. glabratus used in these studies apparently represent different genetic populations with regard to this character, at least insofar as the Puerto Rican strain of parasite is concerned. |
| Databáze: | OpenAIRE |
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