DIG-3 Cry Toxin Variants Overcome Insect Resistance
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Solution Overview
Problem
The development of resistant insect populations threatens the long-term durability of Cry proteins in controlling European corn borer and other pests, necessitating the discovery of new high-potency Cry proteins with different modes of action to prevent resistance and maintain the effectiveness of B.t. technology for insect pest control.
Innovation Solution
The development of the DIG-3 toxin and its variants, which are active against resistant populations of European corn borer and diamondback moth, and can be used alone or in combination with other Cry toxins to control Lepidopteran pests, including the use of RNAi methodologies for pest control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Cry1Ab, Cry1Ac, or Cry1F proteins are used to control European corn borer, then commercial levels of efficacy are achieved, but insect resistance develops threatening long-term durability
Solution Approach 1:
The patent segments the problem of insect resistance by developing multiple distinct Cry toxin variants (DIG-3 and related proteins) with different amino acid sequences and modes of action. Instead of relying on a single Cry protein, the solution divides pest control into multiple targeted approaches using toxins that bind to different receptor proteins in the insect midgut, thereby preventing resistance development through diversification of the control mechanism.
Solution Approach 2:
The patent applies parameter changes by systematically modifying the amino acid sequences of Cry toxin proteins to create variants with altered binding specificities. Through genetic engineering, specific residues are changed to modify how these toxins interact with insect receptor proteins, thereby changing the mode of action while maintaining insecticidal activity. This allows the same basic toxin structure to target different resistance mechanisms.
2Reliability
If new Cry proteins are discovered to control resistant populations, then activity against resistant insects is achieved, but the complexity of identifying and developing new toxins increases
Solution Approach 1:
The patent creates universal Cry toxin platforms that can address multiple resistance scenarios. The DIG-3 and related toxin variants are designed with modular characteristics where core structural elements remain consistent while specific functional regions can be adjusted. This multi-functional approach allows a single toxin family to target various Lepidopteran pests and overcome different resistance mechanisms, reducing the need to develop entirely new toxins for each resistance case.
Data Source
AI summary
DIG-3 Cry toxins, polynucleotides encoding such toxins, and transgenic plants that produce such toxins are useful to control insect pests.