Dormouse Telomeres and Cat Tongues
The caps at the end of our DNA—known as telomeres—shorten with each cell replication. For this reason, telomeres have been used as a marker of aging. But researchers reporting in the journal Scientific Reports discovered one animal whose telomere length increases with age—the dormouse. Amy Nordrum, from IEEE Spectrum, fills in this story and other science headlines from the week.
Amy Nordrum is commissioning editor at MIT Technology Review. Previously, she was News Editor at IEEE Spectrum in New York City.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. You may have heard about telomeres. There the little protective caps at the end of DNA, and these telomeres get shorter and shorter with age.
Scientists use the length of these caps to give you a biological age. There’s even a personal genomics company out there that claims to tell you, well, how well you’re aging through your telomeres– what your telomere age is. But there there’s one animal that might be able to reverse this process.
My next guest is here with news of the animal that holds the key to this genetic fountain of youth– along with other selected short subjects in science. Amy Nordrum is an associate editor at the IEEE Spectrum. She’s here in our community studios. Welcome back. Good to see you.
AMY NORDRUM: Thanks, Ira.
IRA FLATOW: Did you have a good holiday?
AMY NORDRUM: I had a great one.
IRA FLATOW: That’s great. Let’s talk about– so what animals work out– what are we talking about that’s reversing?
AMY NORDRUM: Well, the edible dormouse, it turns out.
IRA FLATOW: The what?
AMY NORDRUM: The edible dormouse, so named because apparently the Romans used to keep these in clay pots and fatten them up with nuts in order to eat them. Little tiny rodent that’s found in the Western European region. These guys have the remarkable ability to actually lengthen their telomeres over time.
There’s a study out of Vienna from the University of Veterinary Medicine there. Researchers put 130 nest boxes out in the woods and tested cheek swabs from these edible door mice over the course of three years to measure their telomere length over that time. They actually found that the telomeres shorten for the first couple of years of the mice’s life, just like they do in most animals, but between the ages of 6 and 9, the telomerase actually lengthen, which is very unusual. So this is the first time they think anybody has observed such a phenomenon in the wild.
IRA FLATOW: And do we have any idea why they’re able to do this?
AMY NORDRUM: We don’t really know, but they have a theory, and that theory is that the edible door mice have an interesting reproductive strategy where they do not reproduce in years when the food supply is low. And this probably leads them to reproduce later in life than the average rodent.
And that’s a problem because reproduction is also known to shorten your telomeres. So they might have evolved a strategy by which they can actually lengthen their telomeres at a time when they would otherwise be vulnerable with age and with late reproduction to actually having them shortened. This might be a strategy that helps them preserve their telomeres’ condition over time. And it seems to be working– door mice can live up to 13 years old.
IRA FLATOW: 13? And the regular mouse is much shorter than that?
AMY NORDRUM: Just a few years, maybe two or three, maybe four. So it’s pretty remarkable extension of their lifespan.
IRA FLATOW: Now I know because we’ve done stories about the naked mole rat. It’s not as cute, but it can live up to 30 years. Do you know if the naked mole rat– if that’s a similar type of thing going on there?
AMY NORDRUM: Well, the naked mole rat has a couple different strategies that it uses for such a long life. So for one, it lives underground almost all the time, so it’s immune to predators and being found by them. Another thing is that it seems to really not be so subject to cancer. And many, many mice die from cancer– almost all of them.
So the mole rat has, perhaps, evolved a strategy to prevent dying from cancer. And some scientists have suggested that it expresses a certain gene whereby the cells in the naked mole rat can kind of sense when they’re overcrowding themselves and stop replicating. And that’s key to preventing cancer, they think, because obviously cell replication, getting out of control, is something that leads to cancer in mice and other animals.
IRA FLATOW: Hm, interesting. Let’s go to another subject. I know that you visited a company that is working to develop wireless broadband– not cellular phones– something different.
AMY NORDRUM: That’s right. This is something different. So it’s like the broadband internet that you get at home on your laptop or your desktop, hopefully. This is a company called Stari, based out of Boston, Massachusetts. And they’ve been experimenting since the start of this year with a really innovative way to deliver a broadband internet.
Now, usually, we have to go out and dig up a bunch of streets and install these fiber optic cables under buildings to pipe internet service to people’s homes for these high speeds that we want with broadband, but Stari thinks that they can do it over the air through base stations, kind of similar to what you would have seen on a cellular network.
IRA FLATOW: So, like, on a cell tower, you would have one of these transmitters?
AMY NORDRUM: Right. Exactly. And one of Stari’s proprietary kind of custom-built base stations.
And then they have a particularly interesting way of receiving internet, so they ask customers to install an antenna outside their window that captures the signal and brings it into their homes. They’re using here high frequency millimeter waves, which are a section of the spectrum that really hasn’t been used before for anything else. There’s a lot of extra bandwidth. And if they can pull it off, this could be a much cheaper way to deliver really fast internet.
IRA FLATOW: So we’re talking about a pilot program right now in Boston?
AMY NORDRUM: Right now, they have only installed one base station. I went up and saw it on the roof of a data center.
IRA FLATOW: And equals 1.
AMY NORDRUM: Right. But they hope to expand that trial to maybe a half dozen sites by middle of next year and sign up some beta customers in the Boston area. Then they’ve applied for licenses from the FCC to do more tests in about 14 different cities across the US including Chicago, Denver, Seattle, and LA.
IRA FLATOW: And the head of this company is the guy who created Arrow right, to disrupt cable TV but the Supreme Court said uh-uh.
AMY NORDRUM: It’s the same guy.
IRA FLATOW: Same guy.
AMY NORDRUM: He shouldn’t run into the same exact challenges in this case. You know, the TV broadcasters, cable providers were asking him to pay licensing fees for the content that he was broadcasting. In this case, he’s just hoping to send internet signal. But he will face competition. There’s a lot of other companies, including Verizon and AT&T, that are hoping to do a similar thing. So it’s good that they’re already in beta because the competition is going to heat up.
IRA FLATOW: Yeah, the big guys come in. And your last story puts a twist on this saying, cat got your tongue? This is interesting about cats.
AMY NORDRUM: Absolutely. Cats are highly evolved creatures, if you think about it. I mean, their paw are suited to helping them creep around very quietly. They have this remarkable ability to twist themselves around in the air when they’re falling and so that they can land on their feet.
And it turns out their tongues are also highly evolved to help them with grooming, which is something that they spend about 50% of their waking hours doing. So I talked with a Ph.D. candidate at the Georgia Institute of Technology, Alexis Noel, who’s been looking into this matter of cat tongues and how they’re so well adapted to grooming.
And she describes these spikes, carotene spikes, that are on the surface of their tongue. These spikes lay flat most of the time, but the cats have the ability to flex their tongue in such a way that they pop up when they start to groom. And the spikes are curved on the end, so that when they pull them through a tangle in their fur, they can actually pull out that tangle pretty effectively.
IRA FLATOW: Sounds like Velcro, like their tongues are made out of one side of the Velcro pad.
AMY NORDRUM: It is. It’s really remarkable– a very effective grooming technique. And there’s 200 or 300 of these spikes on any cat’s tongue, so it’s pretty high density. And, you know, the strategy of laying them flat and keeping them out of the way for the rest of the time is a pretty clever one.
IRA FLATOW: But it would also explain why cats get so many hairballs because they’re so good. These spikes really pull the stuff.
AMY NORDRUM: Right. I mean, that’s the hazard of having basically a hairbrush on your tongue is there hairs that get stuck in their mouth. And the next step for Alexis will be– she’s trying to actually figure out what goes on in the cat’s mouth when those spikes lay flat. She thinks that’s when the hairs, you know, slide down the back of the cat’s throat.
But it’s tough to get inside the mouth of a cat. It’s hard to put a video camera in there. So she’s going to look into trying to use some x-ray technology to figure out what’s going on inside of those cats’ mouths.
IRA FLATOW: They do have a mind of their own.
AMY NORDRUM: They are notoriously difficult test subjects. It’s really hard to get a cat to do what you want it to do. IRA FLATOW: Well, we’ll stay tuned and see what happens. I guess you can’t try this at home. Amy Nordrum, thank you.
AMY NORDRUM: Thank you.
IRA FLATOW: Amy is associate editor at The IEEE Spectrum right here in New York.