In vivo binding of the Cry11Bb toxin of Bacillus thuringiensis subsp. medellin to the midgut of mosquito larvae (Diptera: Culicidae)
Mem. Inst. Oswaldo Cruz
;
99(1): 73-79, Feb. 2004. ilus
Article
in English
| LILACS
| ID: lil-356447
RESUMO
Bacillus thuringiensis subsp. medellin produces numerous proteins among which 94 kDa known as Cry11Bb, has mosquitocidal activity. The mode of action of the Cry11 proteins has been described as similar to those of the Cry1 toxins, nevertheless, the mechanism of action is still not clear. In this study we investigated the in vivo binding of the Cry11Bb toxin to the midgut of the insect species Anopheles albimanus, Aedes aegypti, and Culex quinquefasciatus by immunohistochemical analysis. Spodoptera frugiperda was included as negative control. The Cry11Bb protein was detected on the apical microvilli of the midgut epithelial cells, mostly on the posterior midgut and gastric caeca of the three mosquito species. Additionally, the toxin was detected in the Malpighian tubules of An. albimanus, Ae. aegypti, Cx. quinquefasciatus, and in the basal membrane of the epithelial cells of Ae. aegypti midgut. No toxin accumulation was observed in the peritrophic membrane of any of the mosquito species studied. These results confirm that the primary site of action of the Cry11 toxins is the apical membrane of the midgut epithelial cells of mosquito larvae.
Full text:
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Index:
LILACS (Americas)
Main subject:
Culicidae
Limits:
Animals
Language:
English
Journal:
Mem. Inst. Oswaldo Cruz
Journal subject:
Tropical Medicine
/
Parasitology
Year:
2004
Type:
Article
Affiliation country:
Colombia
Institution/Affiliation country:
Corporación para Investigaciones Biológicas/CO
/
Universidad Pontificia Bolivariana/CO
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