Last week we talked about how the smallest creatures behave in space, but now we move up in size a little to small animals, like mice. What missions have they flown on, and how does microgravity affect their biology?
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Astronomy Cast Episode 446: Animals in Space; Mice and Other Small Animals. Welcome to Astronomy Cast, our weekly fact-based journey through the cosmos where we help you understand not only what we know but how we know what we know. My name is Fraser Cain. I’m the publisher of Universe Today. With me is Dr. Pamela Gay, the Director of Technology and Citizen Science at the Astronomical Society of the Pacific and the Director of CosmoQuest. Hey, Pamela. How are you doing?
Pamela: I’m doing well. How are you doing?
Fraser: Great. So, good news everybody. We have our Patreon.
Pamela: It’s true.
Fraser: I set up my Patreon for Universe Today I think three years ago now, a little over three years ago, and people were like, “When are you gonna set one up for Astronomy Cast?” The reality is that sort of the way donations worked with the way CosmoQuest and Astrosphere–
Pamela: Things have evolved. It’s that simple.
Fraser: Right. It was a very complicated situation. Now things are simpler and, most importantly, we have our Patreon Campaign. So, if you go to Patreon.com/astronomycast, you can see our brand new Patreon Campaign which, right now, there are zero patrons, zero dollars per month.
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We’ve got some really interesting rewards. Pamela just put up the heart. I’m just gonna show people what the Patreon looks like. Astronomy Cast is creating your facts-based journey through the cosmos, also podcasts, and videos. So, we’ve got a bunch of levels. I think Pamela – Yeah, Pamela said online office hours with Pamela once a – what at the $5.00 level. So, you just come. She’ll be like marking papers and then you can come in and hang out and ask her all of your homework questions.
Pamela: Yeah. We’re gonna start doing that roughly weekly when I’m in town and when our show is active. So, support us. Come pick my brain a little more than you already do.
Fraser: I may or may not come and hang out. That’s just another time commitment, but anyway, I think it’s great. I think it’s great that Pamela is there. So, Patreon.com/astronomycast – we’re ready to accept your donations and we really appreciate all of your support. Alright. Shall we get on with the rest of the show?
Fraser: Here we go. So, last week we talked about how the smallest creatures behave in space – the insects and the spiders – and now we move up in size a little to small animals, like mice. What missions have they flown on and how does microgravity affect their biology? Where do you want to start on this one?
Pamela: Quail eggs. I want to start with quail eggs.
Fraser: You want to start with quail eggs? Sure, that sounds great.
Pamela: It’s the one that I found the most amusing and sad. All of these are sad, but it was also amusing. So, we’ll start at the one that’s amusing and sad instead of just sad. So, quails. Quails have high nutrition value. They also start as eggs. Both of these things are useful for understanding the future of quails in space.
Fraser: Quails in space. I suspect I’m gonna be saying with almost every one of these animals that animal in space, but please continue.
Pamela: Right. So–
Fraser: Quails in space. Sorry, I’ll get that out of my system.
Pamela: It’s alright. So, very specifically, Japanese quails in space. This particular kind of quail has a higher than normal lysosome content in its eggs and it is a little critter, so small bodies, small eggs, and it has a high nutrition content. So, the thought was food. We have future food. Food is a positive thing.
Fraser: Future space quail food?
Pamela: Quail is good eats. So, the Russians have been launching quails for a long time and–
Fraser: For a long time?
Pamela: So, the first avian experiments were all the way back in 1979. So, they sent up incubator, they tried to hatch eggs, and they ran into problems that some of you out there with small children and big hearts might have experience. This is when you have a baby bird that doesn’t have a mama bird, you have to feed the baby bird every two hours. So, these poor cosmonauts were every two hours hand feeding baby quails. So, over the years, they evolved to figure out better and better ways to do this because I mean these guys were like handholding, drop letting in.
So, they eventually figured out how to make little sweater basically for the quails that would mount them on little things that would prevent them from suffering under zero gravity too much and would more auto-feed them. So, it allowed the birds to eat for themselves because it turns out that if you’re flapping and you don’t have the ability to grab onto the walls of your container, life is hard.
Fraser: So, they gave them little Velcro sweaters to attach them to the side of a place where they could feed themselves?
Pamela: It wasn’t quite like that. It was more they took the yarn plastic netting that any of you that do yarn art are probably familiar with and they made a little sweater out of this plastic webbing and this allowed them to essentially mount the birds so that the birds would not flop around in space. So, yeah, they ran into different difficulties. So, first of all, there’s the feeding birds is hard. It’s very hard and the birds that did develop didn’t exactly do very well.
There was a great deal of suffering, even once they got the sweaters. So, there was a lot of bird euthanasia. They also ran into problems where, when they did have adult birds – they didn’t only launch eggs – they were hoping to get mating going because if you want to have a food supply, you have to have refurbishment of your food supply. It turns out that hens and roosters – even of the quail variety – are rather apathetic toward one another while in space. So, there was that. Then, in general, they just had a whole lot of trouble getting viable chickens.
So, it turned out that first of all cosmonauts and astronauts aren’t always the best with chicken eggs, but even those who were the best with chicken and quail – whatever kind of eggs – they were only able to get a 60 percent hatch rate and the majority of the little eggs just didn’t develop correctly. So, yeah quails aren’t a really great food source.
Fraser: Right, okay.
Pamela: But they’re adorbs.
Fraser: Yeah, I’m imagining these poor little quails, these plastic sweaters, floating around in space trying to find food or the poor cosmonauts having to set a timer and showing up and feeding these little baby quails. It just really wasn’t the best thought-out idea, but I mean that’s how you push the boundaries of space exploration.
Pamela: I think it was actually a really well-thought out idea until the reality of every two hours hits. Many of us have made this mistake with the critter we rescued from the lawn and reality always carries a club and the idea of food source. Food source is a great idea and the sweaters did allow them to mount the bird onto a surface and auto-feed. So, the sweaters were a great idea. Unfortunately, they just couldn’t get them interested in one another or surviving and those are two kind of key factors.
Fraser: That is truly a haunting vision of the future. You’ve really set I think the tone for this episode of Astronomy Cast. Please continue.
Pamela: It only gets worse.
Fraser: With what happened next?
Pamela: Well, so that’s the story of the quails and it turns out the reason that a lot of these experiments get done is we’re trying to solve a variety of different problems. So, the reason that we take these larger life forms into space is we’re trying to sort what is causing human immune systems to just not do that great in space. What are the other biological side effects?
Skin breakdown, which I didn’t know was a thing, but they learned from studying generations of mice in space that your skin actually starts to atrophy, as well as your muscles and your bones decalcify and with fish, they were able to embed special genetics that made them have markers so that they could watch in real time as the bones degenerated in these fish. They were trying to understand can things that are born in space survive on earth? So, even jellyfish they had problems with.
Fraser: And their bones are already jelly.
Pamela: Right, right. You’d think a jellyfish would not be an issue, but it turns out jellyfish can get vertigo. So, one of the reasons that human beings get vertigo is we have little tiny crystals in our ears that are surrounded by little tiny hairs that aren’t protected like the hairs on our heads but are there rather as sensors to sense how the crystals move around.
Well, jellyfish in the edges of their jelly dome-ness have these little pockets filled with little hairs with little crystals, but while on earth these tell them, “I am an upright jellyfish. I am a sideways jellyfish.” It turns out in space these don’t develop right. So, you bring a jellyfish back to earth and it literally doesn’t know which way is up.
Fraser: Right. Okay, so jellyfish, fish, what other small creatures have been to space?
Pamela: Stabby newts.
Fraser: A stabby newt? I didn’t even know that was a thing.
Pamela: I didn’t either. I’m really loving the research aspect of this. I’m very depressed for the animals, very depressed for the animals.
Fraser: Yeah, you keep in mind the life expectancy of every one of these animals was short. It was not the sort of honor and dignity of the human astronauts. It was they were – we were to find out how living meat performs in space.
Pamela: Yeah, exactly, exactly. So, there’s a kind of newt called an Iberian ribbed newt and the way these stabby newts defend themselves is their bones are actually poisonous and they can jab their bones through their skin – which seems like a really bad thing to do even if you’re a newt – and they user their poisonous bones to defend themselves by stabbing things.
Fraser: Well, I’m sure they’re immune to their own poison.
Pamela: Yeah, but would you want to stab your bones through your skin?
Fraser: No, it sounds like Wolverine or something, right?
Pamela: Yes. Well, so these stabby newts have other kind of awesome characteristics and one of those is that the female newt has the ability – and here we’re gonna use proper biological terms. The female newt has the ability to store viable male sperm and fertilize her eggs later, which means that they had the ability to take female newt into space and then watch female newt lay eggs and watch those eggs develop.
This is a great way to get at the whole development process, especially since amphibian eggs, for the most part, allow you to watch development. So, they happily watched these eggs get laid in space and watched the little baby newt develop and it turned out that heads don’t like to develop on stabby newts in space. So, many of these Iberian ribbed newts, during their development process, developed either shrunken heads or no heads.
Fraser: Oh, you need your head.
Pamela: You need a head and those that did manage to develop a head normally lived, at least as far as the water larval stage. Newts go through a period where they live strictly in water like frogs do, but it was one of these things where there were definite developmental issues that occurred. So, here you have quail eggs don’t develop right in space – high mortality rate. With the quails, you had organs in the wrong place, things that didn’t develop correctly, all sorts of issues. With the newts, you need a head.
Fraser: So, are you saying that perhaps our experiments on animals have led us to perhaps the conclusion that attempting to go through the entire life cycle in microgravity is a dangerous thing and you’re not–
Pamela: I might be saying that.
Fraser: And you’re not gonna get the kind of results that one would hope for that people should not maybe be pregnant in space and carry their babies to term?
Pamela: Yeah, I might be saying that.
Fraser: Yeah, yeah. I mean nobody has tried this with human beings yet, but I think we’ve seen what happens with animals and the animal analogs are not pretty.
Pamela: But to return to silly because we need that. We need that.
Fraser: Yeah, yeah. Let’s not focus on the horror show of headless newts. Please continue. What’s the silliness?
Pamela: They also took adult frogs into space and adult frogs do not know what to make of zero gravity and adult frogs have big legs. You can shift yourself around by essentially moving around your center of mass and watching the astronauts try and figure out how to release a frog so that it wouldn’t jettison itself across the containment vessel, but so that they could watch how it reacted to 0G, makes for a hilarious video. So, what they had was happy little frogs – I’m imbibing emotions onto the frog.
Fraser: Yeah, I think you’re putting a few that maybe shouldn’t be there.
Pamela: So, they had frogs in small containment vessels where the frogs could hang out and touch the walls, which is a good characteristic in space, and then they removed frog from the little containment vessel using sleeves to go into containment so that frogs could not escape into the spacecraft. Then the trick was they were trying to see how a frog would cope with zero gravity without having walls to touch and the problem they had was picking up a frog and letting go of it before it could jump with its legs off of the hand of the astronaut.
So, there were many trials where they’re handling the frog and the frog is like, “I’m out of here. I am just out of here” and jumped for all it was worth and then ended up ricocheting all around the inside of the containment vessel, while the astronaut is trying to grab the frog. Now the frog did not hurt itself in this process. So, you can laugh at the unhurt frog. Then, when they were finally able to release the frog without it jumping off of the person’s hand, it tried to swim. It did the whole swimmy thing with its arms and legs.
So, frogs while knowing they’re in air have somehow gotten the impression of, “Well, I don’t feel a wall so I’m going to try and swim now.” It’s interesting to see the psychology of how these different critters are dealing with this really weird situation.
Fraser: While you were explaining that, I found the video and was displaying it live for the people who are watching and I apologize if I’m distracted now as we carry out this part of show because I wasn’t listening to a word you were saying. I was watching frogs float around in space and that was a hell of a thing.
Pamela: It’s hilarious. Yes, we got to go back to silly.
Fraser: It’s not hilarious. It’s sad, but also hilarious. Let’s move on. So, we got frogs, we’ve got quails, we’ve got – let’s talk about mice.
Pamela: Mice have gone up in many different ways over many, many different years and it turns out that mice have all the problems that human beings have in space, but they’re tiny and short-lived. So, they have done things like we know that human beings’ immune systems come back somewhat compromised from space and we’re trying to understand why.
It’s easier to look at how a mouse’s stuff changes over time – what genes end up getting expressed – because you can very carefully control the genetics of mice and then launch a whole bunch into space that have very similar genetics and they’ve been looking at things like how did the T cells and B cells that make up our immune system get turned on and turned off? It turns out that our entire immune system, and by “our,” I mean well astronauts suffer but mice suffer too. The immune system gets changed in how it functions in space.
This is epigenetics in action where your environment controls to a certain degree what genes are and aren’t turned on. They also looked at not just skeletal degradation, which we’ve seen with the astronauts. We know that there’s decalcification. We know that the human skeleton just gets weaker from time in space. Well, they found with mice that skin also has the problem of breaking down in space.
So, our skin is getting degraded as well. That is also not really good for long term staying in space because, like you need your head, you need your skin and so there’s all of these things that they’ve looked at across generations of mice and looking at baby mice, they also find the mice don’t develop right in space. So, now we have mammals don’t develop right, amphibians don’t develop right, jellyfish are–
Fraser: They never even recover.
Pamela: Right, and newt have issues so–
Fraser: But humans are gonna be okay.
Pamela: This is why we look at all of these different critters because it allows us to start figuring out what are all of the different pathways because there are genetic similarities across all these different critters. The most interesting thing I found though is in general lizards are pretty cool with space. Lizards are pretty chill about the experience. They attach themselves to the wall. They climb around inside. They’re good and there have been gecko sex experiments in space.
Fraser: Of course there have.
Pamela: And the Russians were the ones who did this.
Fraser: Of course they did.
Pamela: They sent sex-having lizards into space, so had both the males and the females, and they had infrared cameras to watch things in action and, unfortunately, there was a spacecraft error so the lizards ended up dying in space and weren’t recovered in better than a mummified condition. But this starts to get at what does work.
With other experiments they’ve done, where they’ve sent up essentially small arcs of animals, they found that over longer periods of time, the mice almost inevitably died. So, you could have a beautiful arc in space with habitats designed to keep all the critters going and the mice just didn’t make it, but the lizards, the lizards were fine.
Fraser: The lizards were fine.
Pamela: Or at least as fine as you can be.
Fraser: So, some future reptilian intelligent species will know that perhaps they’ve got a better shot at being able to survive in space, but we mammalians, we’re not gonna do so well. I’m really glad that we don’t monetize these videos on YouTube – all of our videos – because they would be demonetized by the filthy conversation that we’re having on this episode of Astronomy Cast.
Pamela: It’s biology.
Fraser: I know.
Pamela: There are research papers on this stuff.
Fraser: I know and you’re using all of the proper technical terminology, which I think is great. So, mice. There is an experiment that the Russians – I believe it was the Russians – were planning, but they never got around to doing it was to actually – No, no. It wasn’t Russians. It was some other private group.
They wanted to send a bunch of mice up and put them in a centrifuge in space and have that run and see if you can prevent a lot of the problems by actually giving them some kind of artificial gravity and run some centrifuge for a couple of years and see if you can keep them alive. I think it’s really too bad that nobody has run this test. It would be nice to have something uploaded to the International Space Station or something, something carried up there, that could test out some miniature version of artificial gravity because really I mean there is no living in space until this problem gets solved.
Pamela: And one of the things that does slow down the centrifuge experiment getting completed in space is you have two fascinating constraints. One is the thing requires power to do all the rotate-y bits all the time, but the thing is you also have to have two of these going in opposite directions or you have an excess momentum problem.
So, when you spin up one thing of rotating rats, the ISS is very slowly going to start trying to rotate in the other direction. So, you need two systems counterbalancing each other by going in opposite directions. Then it’s a power draw. So, what they have done is experiments where they have things at slightly higher gravities on earth and they compare the higher gravity on earth –which seems to increase the immune system as we discussed in the last episode – with microgravity in space, which seems to do bad things for the immune system. Another thing you need.
Fraser: Because you’re literally falling nonstop.
Fraser: Yeah. Were there any other small creatures that you wanted to talk about going to space?
Pamela: There’s been a ton of small critters, but I think we’ve hit all of the big picture things and the thing to remember is we’re not doing this simply because it’s fun to watch frogs freak out in zero gravity.
Fraser: And it is not. It is a serious, serious business. Do not laugh when you watch this video. The frogs will not appreciate it.
Pamela: I think it’s okay to laugh at the frog. The frog was unharmed.
Pamela: But, at the end of the day, we have to figure out the problems of compromised immunity. We have to figure out the problems of decalcification of the skeleton. We have to figure out why was the mouse skin degrading as well? Skin, we need skin.
Fraser: Where did those newt heads go?
Pamela: Right, and for long-term living in space, we’re gonna need food sources that go beyond plants and this means we need to figure out how to get fish to develop well. Even the fish are struggling in space and I think tilapia are the most discussed cure for needing protein in space and providing fertilizer for plants and, if we can’t get fish to be fine in zero gravity, we’re looking at a protein poor future.
Fraser: It’s interesting. You see tardigrades. Come on, you know.
Pamela: We can’t eat tardigrades. That’s not a dietary plant.
Fraser: Pile them up.
Pamela: Crickets maybe.
Fraser: No. Hold just like a bucket of tardigrades and sprinkle them on your various space pizza. Then you got all the protein you require. It’s funny to think that with water, like if you do have fish in water, they’ve got the water pressure all around them and they’re used to being neutrally buoyant and moving around, but even they clearly have some kind – They keep themselves in a certain orientation.
They do have the ability to sense gravity, even though they’re underwater and you would, in theory, like I don’t know if you’ve ever been underwater like the scuba divers, you lose track of where up is when you’re under water and yet fish can do this.
Pamela: And fish decalcify.
Fraser: Even though they’re not experiencing it, yeah. So, it’s an interesting thing. So, we are definitely going to reach this hard limit where we just can’t thrive in space anymore. We’re done trying to figure out how to get by in zero gravity or microgravity. There’s got to be some kind of technology to solve the gravity problem.
Pamela: Yeah. It’s a challenge.
Fraser: Alright. Next week, we’ll move up–
Pamela: To the sadder story.
Fraser: Do you want to talk – like there are cats, there are dogs, and there’s of course chimps.
Pamela: It’s the critters bigger than a bread box are next week.
Fraser: Okay, alright. I think that’ll probably bring us to the end of this little mini-series. So, it is yeah, next week we’re not gonna pull any punches. I just want to warn everybody next week is gonna be a sad one, but join us.
Pamela: And go laugh at a frog in 0G.
Fraser: No, don’t, don’t. He’s very sensitive about that. Alright. Thanks, Pamela. No one can see you wave on the podcast.
Pamela: Thank you, Fraser.
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Duration: 31 minutes