Analyses of α-amylase and α-glucosidase in the malaria vector mosquito,Anopheles gambiae,as receptors of Cry11Ba toxin of Bacillus thuringiensis subsp. jegathesan

Bacillus thuringiensis subsp. jegathesan produces Cry11Ba crystal protein with high toxicity to mosquito larvae. The Cry11Ba toxicity is dependent on its receptors on mosquito larval midgut epithelial cells. Previously, a cadherin-like protein (AgCad2), aminopeptidase (AgAPN2) and alkaline phosphatase (AgALP1) were reported to be involved in regulation of Cry11Ba toxicity on Anopheles gambiae larvae. Here, the cDNAs encoding α-amylase (AgAmy1) and α-glucosidase (Agm3) were cloned from A. gambiae larva midgut. Both are glycophosphatidylinositol (GPI) anchored proteins on brush border membranes (BBMV). Immunohistochemistry revealed their localization on different regions of the larval midgut. AgAmy1 and Agm3 bound Cry11Ba with high affinity, 37.6 nM and 21.1 nM respectively. Cry11Ba toxicity against A. gambiae larvae was neutralized by both AgAmy1 and Agm3. The results provide evidence that both AgAmy1 and Agm3 function as receptors of Cry11Ba in A. gambiae.     

La pêcherie de civelle (Anguilla anguilla) en Loire (France) en 1987: Evaluation des prises accessoires et impact halieutique. The Glass Eel (Anguilla anguilla) Fishery in the Loire Estuary (France) 1987: Estimate of By Catch and its Effects on Resources

By-catch is estimated by sampling the whole fishery (February to April 1987) on the basis of a survey of the fishing effort: 16 species of commercial interest are considered, among them 3 species are dominant: Flounder, sprat and brown shrimp (98,4% of the 49,3 million individuals). By-catch consists mainly of very young animals (larval or 0-group stages). An attempt is made to consider the ratio between by-catch and the potential natural mortality of juveniles.