Genetically modified mosquitos

[Unorthodox]

Some of you remember me commenting on this back with the Zika hullabaloo

Release modified male mosquitoes with a gene that causes birth defects in their young, and any young that actually survive carry this gene in a feedback loop, causing reduced populations as a result.  Suddenly a disease causing birth defects in humans springs up in the same area.  Funny coincidence. 

Anywho, results are in for the mosquito release program:

https://www.nature.com/articles/s41598-019-49660-6

However, it is clear from the data in Garziera et al.6 that the effectiveness of the release program began to break down after about 18 months, i.e., the population which had been greatly suppressed rebounded to nearly pre-release levels.

Also, introgression may introduce other relevant genes such as for insecticide resistance. The release strain, OX513A, was derived from a laboratory strain originally from Cuba, then outcrossed to a Mexican population7. The three populations forming the tri-hybrid population now in Jacobina (Cuba/Mexico/Brazil) are genetically quite distinct (Extended Data Fig. E2), very likely resulting in a more robust population than the pre-release population due to hybrid vigor.

We tested OX513A and Jacobina before releases for infection rates by one strain each of the dengue and Zika viruses and found no significant differences (Fig. 3).

So, to sum up, the genetically modified mosquitoes ended up transferring genes that included pesticide resistance to in the wild while selectively breeding OUT the intended birth defect gene (the one we wanted), and have created 3 distinct new genomes that could potentially become even more prolific once they start crossbreeding in the wild, all while not reducing the rate of infection.   



 

[DrazharLn]

Interesting. Thanks for posting.

Really should use the precautionary principle with stuff like this.

I doubt the situation is a lot worse than before, though. The appropriate response to mosquitos remains alleviating poverty, improving building quality and removing standing water. Unless the insecticide resistance is very strong then it won't matter very much.

[Unorthodox]

I still argue the appropriate response to mosquitoes in more mosquitoes. 


Edit (ooo look, actual article on it, I had no idea anyone was actively attempting this, exciting!)

https://entomologytoday.org/2019/03/19/toxorhynchites-rutilus-mosquito-appetite-other-mosquitoes/


The trouble is spraying insecticide impacts predators more than the trouble species. 

[DrazharLn]

That's an interesting approach, but still more risky (though perhaps cheaper) than just buillding better houses and draining standing water near people, etc. Something we know works well (because it has been done repeatedly) and has a variety of other positive effects.

[Unorthodox]

Oh, no, it's more for already developed areas, like in Texas where it's being tested.  En Lieu of 'Mosquito abatement programs' (ie fog spraying pesticide across entire swaths of land) 

[DrazharLn]

Cool, well agreed

Shall we write a joint letter to the Texas State Legislature?