How Nuclear Is Stopping Bugs Before They Bite

Zach Adelman Yellow fever mosquito, she can lay a few hundred eggs over her lifespan, malaria mosquito is probably about the same, a few hundred eggs. So, this means that, you know, you can have a bad problem become much worse if there's a lot of places for mosquitoes to breed.

Mary Carpenter This is Fissionary, a show exploring how nuclear powers your world. I'm Mary Carpenter.

Jordan Houghton And I'm Jordan Houghton. Let's. Jump in.

Mary Carpenter Welcome back to Fissionary. This season we're asking one big question. What powers wonder

Jordan Houghton And today's answer? Innovative genetic tools, or more specifically, how pairing nuclear science and insects has the ability to improve global public health. Mary, I don't even know where to start. Our guest today, Dr. Zach Adelman, professor at Texas A&M, one of the most fascinating guests I think we've had. I learned so much I—I learned so much that I don't even know if I want to know what I know now after having this conversation, because I am infinitely more aware of all of the ways insects are, like, seeking to destroy the life we know and love behind the scenes, and the scientists are there using nuclear science to thwart them, which is great. But holy moly, this was an eye opener.

Mary Carpenter Yeah, I have obviously never been a big fan of bugs. I've always been very interested in bugs, I took an entomology class in college—

Jordan Houghton Oh!

Mary Carpenter –which was one of the classes I really remember because our teacher was so interesting. Shout out to Dr. Espli. But, like, I've always been interested in bugs, but I never knew how cunning and smart they were until today.

Jordan Houghton Well, and for our listeners, we really came into this thinking we were gonna talk about mosquitoes because, you know, we were planning this, we're like, wait, nuclear science is helping get rid of mosquitoes, which are the deadliest animal in the world causing deaths from so many different diseases, but like, also just a horrible nuisance, nobody—nobody likes to be outside in the summer getting bit by mosquitoes and it's just—so, we're like, we're gonna talk about this, and learned so much about other insects that nuclear science is helping control, from the screw worm fly to fruit flies and their grave impact on our food ecosystem.

Mary Carpenter Yeah, it's terrifying to think that if they weren't using these techniques and technologies, that our food supply would be drastically impacted. You guys will hear from Dr. Adelman in the episode, but I mean, we wouldn't have the fruit supply, we know it just wouldn't exist, and meat would be heavily impacted. We wouldn't be able to just go to the store and buy a steak. It would be—look a lot different.

Jordan Houghton And he makes a great point about the cost of the meat and the fruit—if we were able to even get any—how much it would cost because the supply would be so short because of the havoc that these insects wreak on populations of cattle, fruit, trees, et cetera, I—I think we should just take our listeners on this journey with us, come on in!

Mary Carpenter Yeah, let's dive in! Dr. Zach Adelman is a geneticist and professor of entomology at Texas A&M University. His work focuses on developing new tools to control mosquito populations and reduce the spread of diseases like dengue, malaria, and Zika. Thanks so much for joining us today, Zach.

Zach Adelman Thanks for having me.

Jordan Houghton Zach, we're really excited to have you. We're talking about this season, what powers wonder. A bug-free world is something that is wondrous to me, but I want to ask you, in your work, what sparks the sense of awe, curiosity?

Zach Adelman Well, I'm really interested in, uh, kind of the interplay between our genome and the world that we live in, right? So, how does the genetic material that's wrapped in our DNA, how is that read, encoded, how does it change over time, and how does that yield all the different forms of life on earth? To me, that's endlessly fascinating.

Mary Carpenter That's cool. Okay, so let's get into what we're here to talk about: mosquitoes one of my least favorite topics, but I'm very excited to talk about what we're gonna talk about today. So, mosquitoes are often seen as simple pests, but your work really reveals how sophisticated they are as a species. What makes them so good at spreading disease and so hard to manage?

Zach Adelman Alright, so first things first, right? What makes it so hard? What makes it so hard to control it? And kind of the biggest misconception I think anybody has about mosquitoes—if I asked you what a mosquito was, you might describe something that flies around and has a whining sound as it goes past your ear and then bites you and then get big red welts afterwards, or maybe you'd get sick if you got something, but in reality, there's more than 3000 known species of mosquitoes. Probably there's even more than that that we haven't even discovered yet, right? And that number is not just, oh wow. There's a lot of different species, i's that they have been around for a really, really long time, and they're really, really genetically diverse. If I put a malaria mosquito next to a dengue mosquito and I showed them to you under a microscope, because they would both look about the same size and they're about the same color—they look very different to me—but I'd say, yeah, how different do these mosquitoes, and I'd be like, yeah. It's another mosquito, but they're more than 200 million years separated evolutionarily, right? And so that would be the equivalent of me looking at a person, like, I'm looking at you guys right now, or myself, and a duck-billed platypus and saying, ah, they're both about the same.

Mary Carpenter Interesting.

Zach Adelman So, to understand how genetically diverse mosquitoes are and how ancient, then you can understand how difficult it is to try to have any means of controlling them, because what works against this species will not work against another one or another one, one by one. They all have their own habits, ecologies, preferences, susceptibilities, lifespans, you know, any behaviors, everything is gonna be pretty unique, all—all these different groups, so you're not trying to control one thing, you're trying control any, and the strategies have to be different, too. The ones that cause the most trouble for us, right, out of those 3000 something species, only a handful, a dozen, a couple dozen, probably cause almost all of the human disease transmission, these are the ones that are really well adapted to people. They'd much rather feed on people than anything else, and they've gotten really, really good at it. Again, when they first started blood feeding, where were we? We were the progenitor of whatever the original mammals were going to be, and they've been following us throughout our evolution, figuring out ways to feed on us without us detecting them, right? So, they secrete all kinds of stuff into your skin—they have to, but it also makes it so you don't feel the bite, so the blood flows easily, so it doesn't clot, all these different strategies so they can get in and get out without being spotted. And so, they can detect you from distance, they can hone in on all kinds of signals that you're giving off—chemicals that are coming off of your skin, your body temperature, this CO2 you breathe, uh, they can see the heat that you're generated, uh, through infrared. They can just hone in on these cues from a long distance and they know how to get in, they know how to get out, and we're just still trying to catch up with all of their tricks.

Jordan Houghton Wait. Like The Predator?

Zach Adelman Yes, like The Predator!

Jordan Houghton Like the movie?

Zach Adelman Yes, exactly like that. There was a really great paper from a group out of, uh, UC Santa Barbara, Craig Montella's group who, who showed that they actually do see infrared.

Mary Carpenter This is so much worse than I thought it was.

Jordan Houghton I know, It really is! I—I came into this and I'm like, hate mosquitoes. Hate they—they create a nuisance, they create disease, and now I'm like, this is grave. This is really dire.

Mary Carpenter Is it true mosquitoes are the deadliest animal on earth?

Zach Adelman Uh, through the transmission of malaria, then yes, because malaria causes so much mortality, going on 500,000 deaths.

Mary Carpenter Wow.

Zach Adelman They're all similar to each other, right? That –

Jordan Houghton Okay.

Zach Adelman One mosquito and another, uh, is, is the same, and they're not, right? So, you have the culex mosquito that you might find in your house, it's small and brown. You have a tiger mosquito that you might find in your backyard and you're like, oh, it's one mosquito, it's another, I react to mosquitoes, or mosquitoes love me. But different species will make you react very differently. You might react to some species, but not to others. Um, and you might be really attractive to some species, but not to others. And so this over-generalization that there's only one thing out there, um, is probably the biggest misconception.

Mary Carpenter So, you've shared that male mosquitoes are expert trackers of female mosquitoes, and that evolution actually does the work. Can you walk us through how that works in the wild or in controlled release programs?

Zach Adelman Sure. So, males, really, they don't drink blood, right? So that's another, maybe misconception that people have, right? So, male mosquitoes are not interested in feeding on you. They don't need your blood, they can't even do it. Their mouth parts are physically not able to penetrate your skin. So, they just need to find females. That's their,--that's their one job in life. And so, there's really two big strategies that different mosquito species use. And again, knowing that there's actually a lot more nuance here, but males that are hunting females based on their sound, right? So, have you ever had a female mosquito, when she's trying to feed on you and she'll just go past your ear, right? And you hear this really high pitch kind of scree or screech. Have you guys heard that before?

Jordan Houghton Yes.

Mary Carpenter Oh, yeah.

Zach Adelman yeah, exactly. So the male can hear that sound from really far away. Right? And he is attuned to try to find that exact pitch because based on the species, they'll always use the exact same pitch because their wings are the same size, they beat at the same frequency, and so he can tone in on that frequency and try to find her, um, to try to mate. And so that's really great when you're talking about a sterile insect technique program where you're releasing males to then go and find those females because, you know, they can hear that from much, much further away. For us, they have to be pretty close to our ear to be able to hear it, but they can hear it from a much longer distance. For other mosquitoes like malaria mosquitoes, the males don't seek females at all. They actually form what's kind of like we call a mating swarm, so like, he'll get dozens or hundreds of males that will all kind of find each other. They form this big kind of cloud of male mosquitoes. And presumably you guys have like walked through somewhere where like there's a cloud of gnats and, like, you walk through it, and you're like, ugh, man. A bunch of those gnats just went in my—that's the same kind of mating form that they use, right? So the females, because you have this swarm of all these males and all their wings are beating at the same frequency, it amplifies the sound so the females can find a swarm and they fly into it. And then there's a big competition from all the males in the swarm to see who can grab her first.

Mary Carpenter Sounds like my worst nightmare. A giant swarm of hundreds of mosquitoes.

Zach Adelman Yeah, but male mosquitoes, so they don't bite. They don't feed on you.

Jordan Houghton This is wild. Okay, so you mentioned sterile insect techniques. Can you give us a quick explanation of what that is and how it's used?

Zach Adelman Sure. So, insects, right? They're a problem because they reproduce fast. They reproduce a lot, right? So, a single yellow fever mosquito, she can lay a few hundred eggs over her lifespan, malaria mosquitoes probably about the same, a few hundred eggs. So, this means that you know, you can have a bad problem, become much worse if there's a lot of places for mosquitoes to breed. And if you ever live in a place that has a lot of rain and then you get a lot of mosquitoes coming out, you know how quickly they can amplify. Their lifespan is pretty short, and so, you know, they only live maybe a couple weeks in nature, and so, over time, if you just rely on them just—their lifespan, they're just gonna be gone in a couple weeks. So, they have to continually reproducing, you're always getting these new generations. And so, this makes them susceptible to a strategy where if you interrupt their ability to reproduce, you can massively affect the population. Right? So, if male mosquitoes, when they meet with a female, the female will then store that sperm that she collects from the male, and she is done, she will—has a special organ in her body where that sperm is kept alive. And then whenever she wants to fertilize her eggs, when she's laying them, she will just draw upon the stash that she keeps of these sperm over the course of the many weeks that she's—wherever week she's alive. And so, if she mates with a male that had been irradiated and is producing all inviable sperm or dead sperm, she doesn't know that. And so, she won't mate again. And she just has an organ full of dead sperm and when she tries to fertilize her eggs, it doesn't work. They don't form embryos. They don't develop into new mosquitoes, and so she'll live out her life—which is only gonna be another week or week and a half or something like that—and then she can't produce any progeny. And if you do that over uh enough time, then you can massively decrease the population.

Mary Carpenter So, tell us how nuclear science and radiation plays a part in the sterile insect techniques.

Zach Adelman Well, we really couldn't do it without it, right. So, this is—this is the linchpin of how you get this kind of sterilization. How do you get these males that are gonna be infertile? And it's been the use of, you know, isotopes—primarily right now, I think what is used is Cobalt 60, which produces nice gamma radiation that can, uh, sterilize the mosquito they're treated when they're basically pupae, which is the metamorphic stage between the swimming larvae and the flying adult, right? And so just like you have a butterfly, it has little cocoon, uh, mosquitoes form the same type of structure, but they can still swim around while they're doing it. But if you irradiate them at that time, they basically can still complete development, they can still become adults, they still look morphologically normal, but the radiation has, uh, damaged their developing germline to the point that they're sterile.

Jordan Houghton So, where did this idea come from? Like, who first thought, what if we use radiation to control insects?

Zach Adelman It wasn't until, you know, the 1920s, we started out with, uh, Herman Mueller, who was a drosophila biologist who realized that—or first established, basically, that principle that if the more radiation you treat these flies with, and he was using x-rays, but it ended up being the similar for gamma rays or other types of radiation based on the decay, uh, the more chromosomal damage you had, the more, uh, lethality and sterility you had in the chromosomes of those flies. And so, that work had been done, and Herman Mueller eventually won the Nobel prize for establishing, right, that radiation causes lethality and chromosome damage. And so, it was Edward Knipling who was an entomologist for the USDA, he was also a former Aggie, so he graduated from Texas A&M from the department that I work for now, who was studying screw worms and who knew a lot about screw worm biology. And he thought that, you know, just treating cows and treating cattle because, uh, the adult screw worm flies, they lay their eggs in wounds, uh, or orifices around, uh, ruminants and then the larvae burrow into the skin, they make these giant wounds that eventually result in the death of that—of the animal. Um, but he spent all his time treating these cows and he is like, man, if we could just get rid of these, these female flies before they get to the cattle, it would be way more effective. So, he knew he wanted to stop them from reproducing, but he didn't know how to do that. And so, he came across Mueller's work and then he put the two and two together and really thought, oh, yeah. Here we have something radiation that can cause sterility, um, if you have a high enough dose and I want sterile flies. And so, he got started with a few other folks there at USDA and got that going.

Mary Carpenter So how successful has sterile insect techniques been on mosquitoes in addressing diseases like malaria, Zika, dengue?

Zach Adelman There's been a lot of successes and sterile insect technique has done really, really wondrous things for a lot of agricultural pests. It has been used for mosquitoes, but I'm—you know, some of the trials have been successful, a lot of them have shown reductions, but this problem is scale and immigration. So, if you're doing a trial in one small area and you basically reduce the population in that area, but mosquitoes can fly in from neighboring areas, they come back, and they produced so fast that the population comes right back out, back again. And so, we really haven't seen a program at the scale that was achieved with the screw worm minority to get rid of it here. Um, and so, so far, sterile insect technique has not been kind of a major force for controlling a different mosquito species. It's been—there's been some successful trials. There's been a lot of, uh, what I would call smaller scale work, which is still really big, like citywide or kind of, you know, maybe a county or things like that, but not across huge geographical spaces yet.

Jordan Houghton Talk about how they handled sterilization techniques in the screw worms geographically.

Zach Adelman Yeah. So that started with some really good proof of concept trials, uh, on a few islands in the early 1950s. And it was the trial in Curacao that really convinced the producers that this was gonna be something successful, right? So, they were able to eradicate the screw worms off an island in the Caribbean through inundated releases that these sterilized screw worm, uh, flies, and, uh, the—the folks in Florida saw that because the Caribbean is right there next to their doorstep. And so, the screw worm, you know, where it was in the US was in, it was in Florida, a little bit on the eastern side, uh, of the southeastern US and then mostly in Texas and whatnot. And so, the Florida folks saw those trials in the Caribbean and said, we need this now, make this happen. And so, then they had the will to kind of scale up and they started eradication to Florida and they were able to get it out of Florida and the southeastern US. And that really caught the attention of the folks in Texas. And then by the mid-1960s, they had pushed it all the way out of the US, out, down the southern border where they held it for a few years and then realized that, you know, they still had to release so many flies, um, you know, a hundred million flies per week, uh, along that Texas-Mexico border, uh, every year to stop them from coming north again and, um, that's when they really started to think, okay, we've done this at such a large scale already. Let's think bigger, right? And so, this required a huge international collaboration, so we worked very closely with the government of Mexico, and then subsequently all the governments of the Central American countries producing, uh, these flies, first in Texas, then in Mexico. And then as we chased them down year by year, by year, starting in the, you know, the, the 1970s all the way through 2001 when, uh, it was declared eradicated from Panama. And then for the past 20, 25 years or so, we've held that line with a factory in Panama producing, you know, 20 to 30 million flies per week, releasing them on the border of the Isthmus of Panama to prevent them being reintroduced from, uh, from—from Columbia.

Jordan Houghton So, they released that many weekly?

Zach Adelman Weekly. Yes.

Jordan Houghton Oh my gosh. Okay, so Mary and I obviously very focused on the mosquitoes, but we we're talking about the screw worm fly. Are there other agricultural pests that this program has helped?

Zach Adelman We basically would not have any fruit in this country if it weren't for the factories that are churning out millions and tens of millions of Mediterranean fruit fly and Mexican fruit fly, uh, along the California and Mexico borders right now.

Jordan Houghton Wow.

Zach Adelman And those are released all the time to keep these things from reinvading. And sometimes they show up and they release a ton, make sure that they don't spread and they eradicate back again, but basically our food supply is kept safe from these releases and these programs started in the 1960s or seventies, and they have been going ever since. Uh, and these factories every week are churning out—there's a facility in Guatemala that can produce a billion flies, uh, per week for some of these, uh, Mediterranean fruit fly programs to protect Guatemala and Mexico and the US from these—and the US has its own plants that produce Mediterranean fruit fly, Mexican fruit fly, and these are released all the time. And we have fruit because—and these flies can destroy 90% of what you've got. Right? And so, they don't eat all of the fruit, but they might feed on it, or they might oviposit near it. They just damage the fruit enough that fungi will grow or other things will grow and destroy the crop, right? So, if they feed a nibble here, they nibble here and they nibble on every little piece, then all of a sudden it's all gone. Right? So, yeah. So, we have fruit in this country because these programs have been running nonstop for, you know, 50 years or more.

Mary Carpenter That's unbelievable. So clearly we're seeing success stories. Do you ever see pushback to these tactics?

Zach Adelman I don't think I've seen any pushback to sterile insect technique. It's nice because in terms of, like, compared to a pesticide, where you can spread a pesticide over an area and basically just kill every possible insect, including all the ones you don't want to kill, right? All the beneficial insects, all the friendly ones, all the pollinators. This is really, really, really specific. These males are only gonna go after females of their own species and no one else. So yeah, I haven't seen any pushback against, um, sterile insect, uh, technique. It's listed as, there's really nothing, nothing about it.

Jordan Houghton You just mentioned pesticides, which was—

Zach Adelman Yes.

Jordan Houghton –was going to be my next question about how—how this compares, and I think the thing that you just mentioned is probably the biggest difference between the two and that you're not just killing everything—

Zach Adelman Mm-hmm.

Jordan Houghton –which includes bugs that are beneficial. Are there any other comparisons between the two? Like, how did the economics shake out? Is it more cost effective to do this, ultimately?

Zach Adelman So it depends on what your starting population is. And, and you know, looking back at the original, um, you know, description of a sterile insect technique and how it works best, it, it tends to work best—again, you need these really high ratios of factory-reared males compared to wild males, right? So, if there's, you know, a certain number of wild males out there, you need to re rearing 10 times more than that, or a hundred times more than that, right? So, if the population of the insect you're trying to control is really, really, really high, it makes it so much harder to produce enough males to get those ratios that you want. And so, it tends to work best when you are able to reduce that population or if it's naturally low. So, sometimes, you might have to come in and use pesticides first to get the population kind of reduced to the point where sterile insect technique can really, —you can get the ratios that you want. So, they're not always exclusive, but for—definitely when you have an introduction. Right? So, a lot of the sterile technique programs we still use in this country are for when we have an introduction where we spot the Mex fly, the Mexican fruit fly, or the medfly in Texas or in California, the populations can be very, very small because it just showed up, right? It just got, you know, imported in. So, that's a great time to hit with sterile insect technique because, you know, it works in your favor. Uh, whereas pesticides are not gonna be very useful then because there's so few of them, chances are you're mostly gonna kill other things and you're not, the pesticide is not gonna reach the one that you wanted. So, sterile insect technique is really great for when you have a small population in the field, and you can produce a lot and you can overwhelm it. Um, but if the populations are already really, really, really high, then you're probably not gonna be able to reach those ratios that you want, and you'll have to turn to other means, like, could be pesticides, could be other—other areas of control.

Mary Carpenter So, you're working in this fascinating space where genetics, ecology, and global health all collide. What do you think is coming next? And what do you see shaping the future of this field?

Zach Adelman So, there's a lot of effort being put right now into ways to make the sterile insect technique last longer and have males that are more fit, right? So, moving beyond Cobalt 60 based irradiation, so now we have access to genome editing tools where we can use to, to more specifically and more targetedly make, uh, changes to the mosquito or whatever fly genome you want that we can encode sterility, uh, as a trait. And this sterility can be conditional upon maybe some cue that we provide, so we don't need a radiation source so we know exactly what the change is gonna be and maybe combining that with some type of genetic system because now we have all these genetic tools where we can say, okay. Under these conditions, we can get males and females in the factory and we change the conditions in the factory and now all of a sudden we only get males and they’re only sterile. And so, these are happening. We have some really good techniques, there's a lot of really productive people in, in the field of, uh, vector biology and, and genome editing that are developing these transgenic strains, uh, that, uh, offer some really good promise to be able to scale up SIT in a way that it hasn't been able to before because you can achieve sex sorting and you can achieve these kind of lethalities. I think there's a lot of attention being paid now to, um, maybe having these guys be more fit. So, coming out of the factory, having them at the—you want them to be able to fly as far as possible, live as long as possible, make them as competitive as possible, and there's more attention being paid there. And then delivery is really changing, right? So, if you are living back 50 or 60 years, you're talking about a biplane flying over an area. Every once in a while somebody pushes out a crate or a cardboard box and then it crashes, hits the ground, and the flies fly out. It's pretty crudely done and results in, you know, a lot of the flies dying in the process, and—another reason why you need really high ratios, but now a lot of these are being delivered by drones, where drones can go to precise areas and then, you know, they'll deliver a release, you know, small quantities of males in over a much larger area, so you don't need the males to disperse as much, right? You have—I release a giant box and expect them to all fly 500 meters in every direction, versus taking, uh, an army of 500 drones with a small amount and releasing them, you know, every—every one kilometer, you can cover a much larger area, you don't need them to fly as far and you can get that same kind of coverage. So, we're seeing now as a lot of these mechanisms and both the genetics of how we make the strains, but also in the delivery systems of how they're—how those programs are delivering to certain areas, and if you tie that to monitoring, now we have these, you know, computer networks that can say, okay, this is where we're detecting the most flies and then we change our releases here, and then, you know, you're getting real-time monitoring data. And so, the computational power lets us make these programs a lot more, uh, nimble, so they can change very quickly based on where the insects are showing up. You can change the number you're releasing in different places much more readily than you—than you could have before.

Mary Carpenter So, how do you communicate the value of this work to funders, to policymakers, and even the public?

Zach Adelman Yeah, I think that you just have to kind of keep the problem alive, right, so people that remember what the problem was, right. These people have to be your strongest advocates. And we see that now with the screw worm, um, as it's—as it resurges and has broken the boundaries at Panama and is heading northward again. Um, and it's kind of rekindling a lot of the fears that it might return to the U.S. It hasn't yet, but there's a fear that it might, and we still have, you know, people that grew up in the 1950s and early 1960s who, you know, maybe they were teenagers, maybe they were kids, but they remember seeing what that looked like and how that impacted their families and their—their organizations. And so these are your advocates to tell you what—what can happen and why we really need to be proactive, and they're the ones who really had the momentum to stop it in the first place, and they're the ones that are your advocates the second time. And we hope that, uh, that the—the powers that be will listen to those folks and help protect them.

Jordan Houghton Okay, wait. They broke the—they broke the border?

Zach Adelman Uh, yeah, a few years back, uh, the—the barrier in Panama broke down and they have, uh, been found in most of central America now and even into Mexico. And so, there's a very large effort now to rescale some of the old production facilities or build new production facilities. And so, the facility in Panama, uh, was meant to be a containment to hold the barrier to produce, you know, the 20, 30, 40 million flies per week. But it's not enough for eradication, right? So, the old factories in Texas and Mexico that could produce a hundred million per week, those had been shut down and shuttered decades ago. And so, now there's an effort to restart some of those factories and get that production going again as it works. Um, but it has to be at the scale to work, and so they're—that’s in progress.

Jordan Houghton Okay, last question for you, and I'm in awe right now because I have just learned so much over the last 45 minutes or so. This has been really educational and fascinating. But, question for you: is there a person, place, or thing that has left you in awe recently?

Zach Adelman I'm really interested in how genomes evolve, how they change, and how changes that occur over evolutionary time lead to new phenotypes and changes in phenotypes and changes in behavior and whatnot. And I was reading this paper where, uh, this group found that when they looked at the genome sequences—because we've sequenced a lot of genomes of different organisms—they looked at genome sequences of primates, right? And so, you know, to monkeys, to gorillas, to people, everybody was sequenced, all these genomes of primates. And looked at this one region, they found this one region where all the primates that have no tail, like—like you and me, we don't have a tail. They had this selfish genetic element that had inserted itself in the middle of a gene, and none of the primates that still have tails had it. And I thought, well, that's an interesting correlation. And they took basically the same type of selfish element and they inserted it using genetic tools into a mouse genome. And mice of course have tails and mice have the same gene that humans have. So, they put it in the exact same spot and it made the exact same disruption. And what do you think happened? The mice lost their tails.

Mary Carpenter No tail.

Zach Adelman And so we. Lost our tails because some selfish genetic element jumped into one spot and changed one of our genes just a little bit, so now we can't make a tail. And all it would take would be for somebody to engineer that right back out of the genome again, and then we could get our tails back.

Mary Carpenter I am mind blown by some of the things you told us, so I'm very excited for our listeners to hear everything you have to say.

Zach Adelman Thank you for having me on.

Jordan Houghton Zach, thank you so much for walking us through a world most of us never think about, and we're incredibly fortunate that we don't have to, and showing us how biology behavior and big systems come together in really powerful ways. Fascinating to hear the history of sterile insect technique, the scientists who thought up using nuclear science to begin with, just fascinating and the incredible impact it's had for me.

Mary Carpenter That is true. I am grateful for the access and honestly, doing this episode has made me so proud to work in this industry. I am so proud of everything that nuclear does. But I'm still not sure I'm gonna be eating a cheeseburger today, at least. Give me a couple days!

Jordan Houghton If you enjoyed this episode, make sure to follow Fissionary on Apple, Spotify or wherever you listen. And while you're at it, please leave us a rating or review. It really helps others discover the show.

Mary Carpenter Thanks for listening! We'll see you next time on Fissionary.