Research opens way to ending malaria
Parasite kills nearly half a million every year meshes them children under the age of five bednets insecticides on a new vaccine have all shown some potential to curb the disease. What if it could be virtually wiped out some early research using gene editing suggests this might be a real possibility Andrew Jack discusses the findings with crtv? Cookson our science editor and leading researcher Austin, but. So Clive tell us about the theory behind this new research as a background we need to remember. There are three very different sorts of organisms involved in transmitting malaria does us humans does the plasma. Jim parasite causes of the disease and the mosquitoes that spread the disease and all three have been targeted and all being targeted and attacking the mosquitoes. Which is what we're talking about. Today has an ancient history. Like draining marshes to stop them. Breeding and more recently in the twentieth century, poisoning them with nasty pesticides. The most recent approach is to use new gene editing technology and Austin Nobel to tell us more about it. And that makes very very precise changes in the mosquitos DNA far more precise than has been possible with the older genetic engineering recombinant DNA tech. Techniques and the various things you can do with that one is to basically crush the populations because they can no longer breed because then they don't get fertile aunt females. We can talk about that later or you can perhaps alter them said that they can no longer transmit the parasite then they'd still be mosquitoes buzzing around and biting, but they'd be harmless. So Austin you've been experimenting with crisper based gene drive at Imperial College. Tell us exactly how the approach works. Sure. So I was quite mentioned there's a couple of different approaches and were particularly focused on once we're we're trying to suppress or reduce the numbers of the particular species of ski does that transmit malaria, and we'd do that by targeting gene that's necessary for the females to develop properly and be able to reproduce. So we knockouts that gene using crisper base system. And it's gene drive. System, which means that that knock odes that disruption is able to spread you know, disproportionate way to the project, and so despite it causing a certain amount of sterility in the females that is still able to spread through a population. If you introduce it at a rare will over successive generations become quite common and gradually sterilize empire journalists or fraction of the female population. You're actually taking the newborn mosquito and doing some initial genetic manipulation in them, and then encouraging them to breed and spread. So to Connecticut engineer mosquito you inject DNA into a freshly laid egg. And then if that works, then you just sort of propagate from there, and so you're not having to do that all the time. But instead you are able to propagate that genetic change over successive generations in and then you would propagate in the field if we get to the point of releases so one of the findings been like so far with using this technique. Well, the most recent results from work that we've published our that we've been able to crash small cage populations of mosquitoes about six hundred mosquitos introducing this construct twenty five percents in the population. And then over either eight or eleven generations that gene spread through the population of actually all the females were sterile. And then there was no progeny in the next generation and generations. So that implies how much time in fact, and how practical to get that transfer in the wild with it's about a month or so per generation between three weeks a month, so less than a year, and is the result of that you get essentially sterile mosquitoes and the com- then reproduce, right? And so the population of those mosquitoes goes down and so malaria transmission goes down 'cause that's a direct function of the numbers of mosquitoes. Another other sorts of gene editing experiments taking place at the moment. Does other work also happening? Imperial college. That is trying to engineer the mosquitoes to be less able to transmit the parasite to interfere with the development of the parasite within the mosquito. Also, I should mention that the large part of the work. We're doing is in the lab of Andrea corr Santi at Imperial College. And so other working his life is to try to skew the sex ratio such that it's mostly male mosquitoes 'cause it's only the females that bite and transmit the disease. So if you can skew the population to be mostly males than that will reduce transmission thoughts about the relative merits of the different approaches.