Researchers have tested using CRISPR to reduce insecticide
resistance in pests. In simple form, this was done by editing the gene which
controls insecticide resistance by returning it to a wild type allele, making
it susceptible to insecticides. This obviously came with ethical concern so the
researchers only made it a temporary solution. Hence, why they returned the
gene to wildtype rather than removing the insecticide-resistant variant genes entirely
by replacing them with susceptibility to pesticide genes. They term for this is
a e-Drive cassette which spreads through CRISPR gene editing which binds to Cas9
DNA and cuts out voltage gated sodium ion channel (vgsc) insecticide resistant gene
site. This solution is not permanent since removing insecticide resistance lowers
fitness of pests.
What the e-Drive essentially does is disable the insecticide
resistance gene by using CRISPR to ensure that the wild-type gene has a 100%
frequency of being passed to offspring. Since the non-resistance gene is being
spread rapidly, it can spread faster than the resistance gene within just a few
generations, 8 to 10 to be specific. Although the cassette was also inserted
with a fitness check which limits viability or fertility. So the wild type gene
spreads, increasing susceptibility and reducing pests (for example on crops),
then over time the added fitness check along with the natural lower fitness
takes over and the non-resistant pests eventually die out. The population
returns to a normal resistant one. The beauty of this e-Drive cassette is that
it can be reintroduced whenever needed, for example, if the pest problems become
large again, then the e-Drive can easily be added back. It is a short term,
effective, easily implemented, and easily removed strategy that the researchers
hope could also work on mosquitos for malaria.
This is a great development because insecticide-resistance
is rapidly spreading throughout populations of pests. While we need to control
pests from destroying things like crops, it is becoming increasingly difficult
to use pesticides to kill them. We also do not want the e-Drive to become out
of control which could seriously harm pest populations. As the researcher says,
this strategy will work without creating any other perturbation to the
environment. If we can successfully increase pesticide effectiveness without
entirely harming a pest population, I am all for it.
Links
https://www.sciencedaily.com/releases/2024/11/241122172740.htm
https://www.epa.gov/pesticide-registration/slowing-and-combating-pest-resistance-pesticides
The mechanism that these researchers used is very interesting! A temporary solution that can be repeated whenever they need is a great idea to ensure fitness and variability for pests. Also, reading about the new uses of CRISPRs always amazes me, and this discovery definitely did too. The idea that the CRISPRs can ensure that the wild-type (non-resistant) gene is guaranteed to be passed down is fascinating, especially in such a short time frame! Overall, these is a very impressive study.
ReplyDeleteThe e-Drive cassette is a smart, temporary fix for insecticide resistance, restoring pests to wild-type susceptibility and balancing pest control with ecological safety. Its potential for mosquito-borne diseases like malaria makes it an exciting, adaptable solution to pesticide resistance.
ReplyDeleteI admire your hope to resolve the issues involving insects that are harmful to crops but making it possible to not harm pest population. This is important because pesticide often kill other insects that are essential to the food web. It also immensely decreases certain isenct populations such as butterflies. So this E-Drive cassette research looks promising especially because it can balance the cost of pesticide use while making it ecologically safer for insect populations in the future. Yet, I wonder what the other ramifications might be.
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