Abstract: The cytA gene encoding the 28 kDa polypeptide of Bacillus thuringiensis israelensis crystals was disrupted in the 72 MDa resident plasmid by in vivo recombination. The absence of the 28 kDa protein in B. thuringiensis israelensis did not affect the crystallization of the other toxic components of the parasporal body. However, the absence of the 28 kDa protein did abolish the hemolytic activity of B. thuringiensis serovar israelensis crystals. The mosquitocidal activity of the 28 kDa protein-free crystals did not differ significantly from the wild-type crystals.

Abstract: The invention relates to a sequence of nucleotides characterized in that it corresponds to the fragment HindIII of about 4.3 kb which can be obtained from the plasmid pJEG80.1 which has been deposited at the CNCM on Aug. 23, 1994 with the number I-1469 or capable of hybridizing in stringent conditions with said plasmid. It also relates to polypeptides resulting from the expression of said sequence and their utilization in toxic compositions against insects.

Abstract: A nucleotide sequence having the following properties: it includes all or part of DNA fragment XbaI of 7 kb shown in FIG. 4A, as obtained from plasmid pCBM1 filed with the CNCM on Jun. 15, 1993 under no. I-1317; it hybridises with oligonucleotide probe 18A (TGT GAA GTI AAT TGT GA) SEQ ID NO:1 and/or oligonucleotide probe 16A (TTT CAT ATI GAA GCI GTI AAT GAA GG) SEQ ID NO:2 and/or at least one of probes 66A (ATG AAT ACI AAT ATI TTT TCI ACI AA) SEQ ID NO:3 or 66B (TC IGG TTC ICC ATA IAT CCA TTC ATC) SEQ ID NO:4 under stringent conditions; and it codes for a protein, polypeptide or peptide capable of participating in the toxic activity of the expression products of fragment XbaI of 7 kb against Diptera larvae and mosquito or sandfly larvae in particular. The polypeptides encoded by said sequence and their use in larvicidal compositions are also disclosed.

Abstract: The cytA gene encoding the 28 kDa polypeptide of Bacillus thuringiensis israelensis crystals was disrupted in the 72 MDa resident plasmid by in vivo recombination. The absence of the 28 kDa protein in B. thuringiensis israelensis did not affect the crystallization of the other toxic components of the parasporal body. However, the absence of the 28 kDa protein did abolish the hemolytic activity of B. thuringiensis serovar israelensis crystals. The mosquitocidal activity of the 28 kDa protein-free crystals did not differ significantly from the wild-type crystals.

Abstract: The cyta gene encoding the 28 kDa polypeptide of Bacillus thuringiensis israelensis crystals was disrupted in the 72 MDa resident plasmid by in vivo recombination. The absence of the 28 kDa protein in B. thuringiensis israelensis did not affect the crystallization of the other toxic components of the parasporal body. However, the absence of the 28 kDa protein did abolish the hemolytic activity of B. thuringiensis serovar israelensis crystals. The mosquitocidal activity of the 28 kDa protein-free crystals did not differ significantly from the wild-type crystals.