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The Cry48Aa‐Cry49Aa binary toxin from Bacillus sphaericus exhibits highly restricted target specificity
Author(s) -
Jones Gareth W.,
Wirth Margaret C.,
Monnerat Rose G.,
Berry Colin
Publication year - 2008
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2008.01667.x
Subject(s) - bacillus sphaericus , biology , culex quinquefasciatus , bacillus thuringiensis , toxin , culex , pore forming toxin , larva , aedes , microbiology and biotechnology , culex pipiens , bacillales , aedes aegypti , microbial toxins , botany , genetics , bacteria , bacillus subtilis
Summary The Cry48Aa/Cry49Aa binary toxin of Bacillus sphaericus was recently discovered by its ability to kill Culex quinquefasciatus mosquito larvae through a novel interaction between its two components. We have investigated the target specificity of this toxin and show it to be non‐toxic to coleopteran, lepidopteran and other dipteran insects, including closely related Aedes and Anopheles mosquitoes. This represents an unusually restricted target range for crystal toxins from either B. sphaericus or Bacillus thuringiensis. Gut extracts from Culex and Aedes larvae show differential processing of the Cry48Aa protein, with the location of cleavage sites in Culex reflecting those previously shown for the activation of Cry4 toxins in mosquitoes. Pre‐activation of Cry48Aa/Cry49Aa with Culex extracts, however, fails to induce toxicity to Aedes larvae. Co‐administration of Cry49Aa with Cry4Aa gives higher than predicted toxicity, perhaps suggesting weak synergism against Culex larvae between Cry49Aa and other three‐domain Cry toxins.