Harnessing the power of nature.
Our technology provides an environmentally-responsible method of controlling
insect pests that spread disease or damage crops.
We call this method “self-limiting” because the released insects and their offspring are designed to die and disappear from the environment.
We release males, because it is the female insects that are directly responsible for spreading disease or producing larvae that damage crops. Our males have one job: to find wild females where they live and mate with them.
The self-limiting gene prevents the insects’ offspring from surviving to adulthood, and a fluorescent marker gene that produces a protein throughout the body of the insects, which glows when you shine a special light on it.
Our technology has several key benefits over other methods:
- Species-specific: Our insects only reproduce with their own species. They will not result in the death of other, beneficial insects – unlike some other methods of control.
- Targeted: Our technology harnesses the natural mating instincts of the males, seeking out the wild pest insects where they live and breed in a way that conventional tools are unable to do.
- Environmentally-responsible: Our technology does not use any chemicals that are harmful to the environment.
- Non-persistent: The self-limiting system means that our insects cannot establish in the ecosystem.
- Non-toxic: The proteins of our introduced genes do not produce any toxins or allergens.
- Scalable: Our innovative production technologies allow us to efficiently mass rear our insects at a large scale.
- Flexible: Our self-limiting insects can be used as part of integrated pest management programs.
The Self-Limiting Gene
The self-limiting gene is at the heart of our method of insect control. When our male insects are released and reproduce with wild females, all of their offspring receive a copy of this gene. The self-limiting gene disrupts the proper functioning of their cells by flooding the insects’ cells with a protein to stop them from properly expressing other essential genes needed for development and preventing the offspring from surviving until adulthood.
Since the self-limiting gene works by using the insect’s own biology against itself, our control method provides a solution that only affects that particular species of pest without introducing harmful toxins.
We have also designed our insects so that we can turn off the self-limiting gene with an antidote called tetracycline. This allows us to breed our insects at a large scale without the need for any additional genetic engineering. Our FriendlyTM Mosquitoes, for example, were engineered in 2002, and we have been breeding the strain from those original mosquitoes ever since!
The Fluorescent marker
We have also introduced a marker gene into our insects, which expresses a protein called DsRed2. Like the self-limiting gene, it is inherited by all offspring. This protein is found throughout the body of the larvae and pupae and glows red under a special light. As a result, you can easily tell our insects apart from wild ones.
The marker gene is vital for a control program, as it allows us to easily identify the offspring of our insects and enable us to track-and-trace them in the wild. By examining larvae from the field, we can see how many are offspring of our self-limiting insects and how many are wild ones. This makes it a highly useful tool for quality control in production and effective monitoring in the field. We then use that data to tailor our releases and ensure we obtain high levels of pest suppression.
Because the marker is integrated into the insects’ DNA, this provides a better monitoring tool than fluorescent dusts or food dyes used in other insect control programs.
1. Self-limiting gene produces tTAV protein
The self-limiting gene creates a protein called a tetracycline-controlled transactivator (tTAV protein). One section of the self-limiting gene contains a binding site called tetO.
2. tTAV protein binds to tetO, producing positive feedback
The tTAV protein binds to the tetO site on the self-limiting gene. This works as positive feedback, telling the gene to create more tTAV. As increasing amounts of the tTAV protein is produced, there is more positive feedback, and so even more protein is created.
3. High levels of tTAV prevent cells from working properly
Once there is enough tTAV protein, it interferes with the machinery that cells use to control the expression of genes. Essential genes are not expressed, and the insects die while they are still pupae or larvae.
In some of our products both male and female insects die, while in others the gene only affects female insects.
4. The self-limiting gene can be turned off with an antidote
When the insects are reared with an antidote called tetracycline, the tTAV protein binds to the antidote instead of tetO. There is no positive feedback so levels of tTAV remain low and the insect survives.
In rearing we can breed our self-limiting insects by adding tetracycline to their food. However, in the wild their offspring do not have access to tetracycline and so they die.
The agricultural application.
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