Tracy Bedrosian talked about her work on transposons, or “jumping genes”, and how they generate variation within the tissues of an animal. She did an excellent job and fielded some really wide-ranging questions, from sharks and cancer to Turbo the snail. A transcript of the Q & A follows.
Student:
Do you remember what your first experiment was with jumping genes?
Tracy:
My first experiment was I took some mice and I put them in a really fun cage that had a lot of toys and it had running wheels and things they could play with, and then what I did was I took some cells from them and I analyzed them to see how many copies of jumping genes were there. We found that mice that had a really fun cage with more opportunities to learn and play had a little more jumping genes than mice that were kept just in a regular old cage that’s kind of boring.
Student:
Do animals have jumping genes?
Tracy:
They do. Most animals have jumping genes just like people but there are some that don’t. There’s one species of bat that has no jumping genes and scientists are very interested in it to know why it has no jumping genes and how that affects it.
Student:
Can jumping genes be good and bad for a body?
Tracy:
So on the one hand maybe jumping genes can tweak the way your cells work and maybe contribute to making us all unique individuals, like contributing to personality, on the other hand, when they jump too much they might contribute to diseases. There was a study that showed that people that had schizophrenia, which is a mental disorder, they had more copies of these jumping genes in their brains. So it could be a bad thing or a good thing.
Student:
So this isn’t about jumping genes but I heard that sharks can never get cancer. Have you known anybody to do research on that?
Tracy:
I didn’t know that, I had never heard that before. I’ll have to look that up myself. I’m sorry I don’t know anything about that.
Student:
In your blood, does it have these sorts of particles that have like energy? Because in this movie, Turbo, the snail became super fast, but there are these particles that made him go faster. Like they’re super slow but then the DNA came into those particles and made them faster.
Tracy:
Well, your blood carries lots of oxygen that’s important for making your brain work and your body work fast, but I don’t know about that with the jumping genes.
Student:
What do you want to know about jumping genes?
Tracy:
Well for one I think it’s cool to know about why people are different from one another and one reason I think that’s important is for understanding diseases of the brain because some people are more susceptible to different mental disorders. Like some people might be more prone to getting depressed or anxious and others don’t really run into that problem. So if we can understand why people’s brains are unique, and that might have something to do with jumping genes or it might not, but if we can understand that it might help us to help those people who have certain mental disorders.
Student:
Are jumping genes in all cells of the body or just neurons?
Tracy:
So they are in every cell of the body but they don’t jump around as much in all cell types. So it turns out that they jump a lot in brain cells and in particular parts of the brain that are important for learning they jump a lot more. So it depends on what region of the brain and what part of the body you’re looking at but they are technically everywhere, it’s just how much they jump.
Student:
So I was thinking about this and I don’t know but can jumping genes change a species like evolve? If there’s enough?
Tracy:
There are people who have wondered about that. It seems that there are a lot less jumping genes that jump in people versus like in chimpanzees and other apes. So people have wondered if they have contributed somehow but it’s not quite known yet.
Student:
Are there other species of animals that have more jumping genes or less than humans?
Tracy:
Definitely. So in people there’s like around a hundred actively jumping copies but say like in mice there’s about 3000 and then you have those bats that don’t have any so there’s definitely a range.
Student:
Can jumping genes be contagious?
Tracy:
No because it’s something that’s in your DNA, it’s not like a virus or something contagious. It’s just something that happens inside your cells naturally. Jumping genes might have come originally from viruses, so that’s a good point that you bring up. There’re certain kinds of viruses that act similarly to the way that jumping genes do, in terms of what they to the DNA and RNA so there could be a relationship but no, jumping genes themselves are natural and part of your cells.
Student:
I was just curious, do crawdads have jumping genes and if so, how many?
Tracy:
Oh my gosh, I don’t know! I don’t know the answer to that one. Sorry!
Student:
Is it possible for a jumping gene to change your body permanently? If you have a bunch of jumping genes in one part of your body could it change that part of your body at all?
Tracy:
So, say in the brain if you have a bunch of jumping genes happen in one particular part of the brain it could maybe change how you act or how you behave. That’s possible but we don’t know the answer for sure yet but that’s kind of what we want to know. But it’s kind of rare, they jump around but it’s kind of a rare thing so they probably wouldn’t have like a huge, huge effect.
Student:
Do plants have jumping genes?
Tracy:
Yes, actually they were first discovered in corn. Because have you ever seen corn kernels where sometimes the corn has different color kernels? That’s why – jumping genes.
Student:
You said that there’s only one species that does not have jumping genes – do you know what that one is?
Tracy:
It’s some kind of bat but I don’t remember exactly what kind of bat it is. It’s one particular kind of bat. I think there’s maybe one other animal that doesn’t have jumping genes, I don’t remember which one though but pretty much every other animal we’ve looked at has some jumping genes.
Student:
Do you think that there are other creatures that have jumping genes, like bugs and all creatures that are living?Tracy:
So most of them have jumping genes except for a few exceptions. Even little fruit flies have jumping genes.