Wouldn't it make sense to go after the root cause rather than merely its host?
- Way (many orders of magnitude) less # of mosquitos than parasite organisms (malaria is a single celled organism, mosquito's are ~1 million celled organisms).
- Mosquito's reproduce sexually, malaria reproduces asexually, someone had a good idea about how to target sexual reproduction.
EDIT/Errata: Malaria is not a virus.
Lack of a vaccine.
The malaria parasite has multiple, immunologically distinct developmental stages and effective immune avoidance strategies. Single-antigen and single-stage vaccines have proved disappointing. Multi-antigen, multistage vaccines, which elicit different kinds of immune responses directed toward different antigens, appear more promising. High antibody levels can be effective against sporozoites and blood-stage parasites, but a cytotoxic cell response is needed to attack the critical liver stage, and antibodies are clearly needed to block transmission. Selecting the optimal antigens from among the stages in the parasite's life cycle and devising optimal formulations and delivery systems to elicit the desired immunologic response is a complex and difficult task, one that must be based on scientific knowledge, but will also require empirical testing of multiple potential vaccine products.
Remember that a vaccine needs to produce an immune response that doesn’t lead to cytokine storm or devestating autoimmune response.
It's more anecdotal than technical, but interesting nonetheless -- I never would have guessed people were volunteering to be given malaria...
Not an expert, but it is #25 on that WHO list.
"Recent progress has been made with the completion of a Phase 3 trial of the RTS,S/AS01 candidate vaccine and review by the European Medicines Agency and WHO. There is currently no commercially available malaria vaccine."
I'm confused. If these mutated insects are unable to reproduce, how do they spread their mutation to the rest of the population?
As more and more female mosquitoes inherit two copies of the modification, more and more become sterile.
So maybe the mutations activate only when inherited from _both_ parents?
This is awesome. It's one of those things that makes you feel like you live in the future. Preventing the spread of Malaria, Zika, West Nile, a bunch of other things... and saving our dogs from heart worms! Not to mention avoiding all the cancer and neurological illnesses we've had to endure thanks to chemicals in repellants we had to use...
I'm sure there are consequences for killing off all the mosquitoes, and we'll have to deal with those... but I for one can't wait to deal with those problems instead of mosquitoes.
Nobody is proposing killing all the mosquitoes, and I doubt it would be possible to do so with the techniques being investigated. Only the specific species of mosquito that carry specific parasites are being targeted. You will not see a reduction in mosquito numbers, as the population of other mosquito species will grow to fill the void.
Or nothing will happen at all. I think I've been reading about tests and trial releases of generically modified mosquitoes for decades, but nothing as far as even discussing the mass releases needed to eradicate the malaria parasite and the disease. And almost nothing unfortunately on the other mosquito born illnesses you cite.
the doublesex gene targeted by this gene drive is similar in all insects, so if this works we'll have a powerful tool not only against mosquitos, but also against all agricultural pests, which is very exciting.
I'd say scary instead of exciting here.
I’m not sure we know the scale of these problems. Historically, messing with the ecological food web like this has often caused more harm than good, so I think it’s worth it to be more careful than this.
It appears the toads have evolved longer legs so they can travel faster and further.
The big problem with the toad is that they are poisonous. Native larger animals eat them and die, which reduces biodiversity and leaves the toads free to grow and expand.
These kinds of experiments of course never have any side-effects...
Humans are pretty pair bonding. It would need selective pressure and would take generations. There would need to be way too many suddenly appearing partners or modifications. Even if it somehow worked to say result in sterility it could be undone. Given that the trap would take generations and the state of the art advances it could well be completely effortlessly defeated because everyone is having genetic diseases and cancer risk factors removed from their children anyway.
It has been my private head canon for a number of years that the Gerudo race in the Legend of Zelda are the result of an attempted gene drive to exterminate Hylians. The fact that their offspring are (almost) exclusively female suggests it, and attaching the modification to a (literal) fitness increase would be a reasonable way to try to help it achieve fixation sooner.
Well, looks like I'm going to have the Gerudo Desert theme stuck in my head for the rest of the night.
Could we undo it? Since CRISPR modifications have side effects, would we feel safe trying to undo it? Where would we draw the line?
If the mad scientist targeted broccoli bitterness, maybe we would let it pass, especially if we detected the attack after hundreds or thousands of people had been affected. The cure could be more dangerous than the disease.
If the mad scientist decided to try to give everyone blue eyes, maybe we'd act more aggressively to undo it?
I don't think the answers are obvious. And since these are not billion-dollar experiments, it could be a real concern.
> Could we undo it? Since CRISPR modifications have side effects, would we feel safe trying to undo it? Where would we draw the line?
We do not even know how to do what you are proposing, so why should we know how to undo it? The only answer here I can give you is that we do not seem to see gene drives in nature a lot. If such a powerful tool would exist, evolution (aka selfish genes) would certainly want to use it but at the same time become very inventive to find strategies against it. For example, endogenous retroviruses are a thing, but we still do not see them in action much.
Why not focus on narrowing down the gene edit so only the biting ability is destroyed, allowing the females to reproduce?
Seems like a safer option in the long run
So our plan is trusting in the reproduction of an sterile animal that is unable to reproduce but must multiply somehow (by budding?) to replace the wild population that 1) do not have any problem to lay eggs or mate, 2) are much more numerous and 3) can suck blood that is needed to bost the egg production.
It seems that this plan has some loopholes...
this is a must watch for anyone wondering if there might be "side-effects" https://www.youtube.com/watch?v=yzDISuJdfZk
In theory, the other mosquito species will adapt to fill the niches that the controlled species once occupied.
The precautionary principle is great until it gets a bunch of people killed, which is what happens when we let species like mosquitoes live.
Does that mean you disapprove of the allies fighting WW2 germany by killing their soldiers? We should have attempted to use only non lethal weapons? Or should have just let them commit genocide?
(I know, godwin's law, but it's a relevant uncontroversial example here).
That logic makes me sick.
And what makes anyone think that malaria won't find some other vector that's much harder to control?
I can understand your point of view, I disagree I think just because I have different base moral values here. I attach value to the existence of complex life, but not to individual species (with the possible exception of humans).
If Malaria is going to find a better vector, it will do that anyways. It's more likely to do that while there is more of it (more chances to mutate correctly) so to minimize the risk of that happening one should do their best at killing it off.
IIRC they didn't genetically modify humans to be sterile to prevent the spread of the virus, could be wrong though...
We used to wipe out all kinds of animals that were deemed pests only to find out later on that these animals served a role in an ecosystem.
I personally do not mosquitoes and wouldn't mind if they weren't around. But I hope we are absolutely sure that we know what we are doing and don't regret wiping out these mosquitoes a century later. Hopefully there aren't any unintended consequences.
Don't birds and other insects eat mosquitoes?
How much of it is related to stuff we've done at large scale before understanding the consequences?
By then, it's far too late to undo those changes. The genetic pollution remains forever.
It is therefore far better to have never done any genetic modification at all, because we simply don't understand how one change interacts with everything else.
Nature has done so much better than we have ~ therefore, because we don't understand nature's decision-making process, and never have, and most probably never will, we should never interfere with tinkering with something extremely and profoundly complicated like DNA.
Selective breeding is superior to humans tinkering with the genome directly.
I agree with your concern, but I don't see this technology as fundamentally different from humans have been doing for hundreds of years. We've already released so many chemicals and materials into the environment that have had many harmful and irreversible effects on the environment. Releasing a genetically modified mosquito does raise concerns, but it's not too different from putting some new chemical into the environment, which we do all the time.
Not to mention complex systems are basically impossible to /not/ meddle with. Fish have accidentally been bred smaller because of practices to prevent depletion by giving immature ones a chance to grow to adulthood. Heck there is evidence that fear of humans is bred in animals.
From what I've read, hybridization does occur between mosquito species.
Hybridization rates are not static. What's more, hybrid mosquitoes would in no way be limited to mating with other hybrid mosquitoes.
Consider that this gene drive diminishes the female mosquito's ability to feed on blood. I'd expect it be possible that this would cause modified female mosquitoes to be maladapted in other ways. If modified female mosquitoes were to experience significant additional stress, the adult sex ratio in modified mosquitoes could shift dramatically toward an overbalance of modified males.
If this were to happen, don't you see how it could increase pressure on males to outbreed? E.g. if a large proportion of their natural mates were either dead or malnourished? Similarly, can you see how the same kind of situation might emerge for the hybrids, increasing the likelihood of backcrossing?
A gene drive that specifically disrupts the females' ability to survive seems like it would increase the likelihood of introgression, potentially by a lot.
This whole situation just strikes me as highly unpredictable, risky and poorly understood.
Thank you for the rational comment. I found some of your other posts in this discussion to be emotional enough to make me not take them seriously (although I agree with the need for being cautious with GM). A post like the one above carries a lot more weight than "makes me sick" type comments. It's an emotive subject for sure, but straying too much from a rational tone can be counterproductive.
>If mosquitoes went extinct: Mosquito larvae are very important in aquatic ecology. Many other insects and small fish feed on them and the loss of that food source would cause their numbers to decline as well. Anything that feeds on them, such as game fish, raptorial birds, etc. would in turn suffer too.
Mosquitoes and their lavae are a primary food source for muliple bird, mammal and fish species.
But there are people out here who think they're so smart: to hell with the big picture, to hell with ecology, to hell even with consensus and consent. They are certain that they know what's best for the planet, for sexually reproducing life forms in general, and for humans. So they are forging ahead whether you or I like it or not.
I feel hopeless about it.