Modified Cry3A Toxins and Nucleic Acid Sequences Coding Therefor
AssigneeSyngenta Participations AG
InventorsEric Chen, Cheryl Stacy
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Abstract
Methods for making a modified Cry3A toxin are disclosed. Such methods include the insertion of a protease recognition site that is recognized by a gut protease of a target insect, such as corn rootworm, into at least one position of a Cry3A toxin so that a modified Cry3A toxin is thus designed. The coding sequence of the modified Cry3A toxin may be transformed into a host cell and the host cell grown under conditions that allow the host cell to produce the modified Cry3A toxin. The host cell may be a plant cell and the plant may be comprised in a transgenic plant. Thus, the transgenic plant may be used to produce the modified Cry3A toxin.
Claims23
An isolated nucleic acid molecule comprising a nucleotide sequence that encodes a modified Cry3A toxin comprising a non-naturally occurring protease recognition site, wherein said protease recognition site modifies a Cry3A toxin and is located at a position between amino acids corresponding to amino acid numbers 107 and 111 of SEQ ID NO:4, wherein said protease recognition site is recognizable by a gut protease of western corn rootworm, and wherein said modified Cry3A toxin causes higher mortality to western corn rootworm than the mortality caused by said Cry3A toxin to western corn rootworm in an artificial diet bioassay.
A modified Cry3A toxin comprising a non-naturally occurring protease recognition site, wherein said protease recognition site modifies a Cry3A toxin and is located at a position between amino acids corresponding to amino acid numbers 107 and 111 of SEQ ID NO:4, wherein said protease recognition site is recognizable by a gut protease of western corn rootworm, and wherein said modified Cry3A toxin causes higher mortality to western corn rootworm than the mortality caused by said Cry3A toxin to western corn rootworm in an artificial diet bioassay.
A method of making a modified Cry3A toxin, comprising:
- (a) obtaining a cry3A gene which encodes a Cry3A toxin;
- (b) obtaining a nucleotide sequence which encodes a protease recognition site;
- (c) inserting said nucleotide sequence into said cry3A gene, such that said protease recognition site is located in said Cry3A toxin at a position between amino acids corresponding to amino acid numbers 107 and 111 thus creating a modified Cry3A gene;
- (d) inserting said modified Cry3A gene into an expression cassette;
- and
- (e) transforming said expression cassette into a non-human host cell, wherein said host cell produces a modified Cry3A toxin.
Dependencies are inferred from the claim text.