11 April, 2012

A-Z Blogging Challenge: Jumping Genes

Barbara McClintock. Public domain image. SOURCE.
Jumping genes, also called transposons or transposable elements (TEs), are genes that move from one place to another along chromosomes.

Transposons were first noticed in maize, which is sometimes mottled with different colors. The observed colors did not follow Mendelian genetics (Gregor Mendel was a friar, commonly called the Father of Genetics) which predicted colors based on the arrangement of chromosomes during meiosis (cell division). A new theory was required and it was developed by Barbara McClintock, who was consequently awarded the Nobel Prize in Medicine in 1983 for her work.

It was discovered that transposons are present in close to all living organisms and constitute 50% of human genes and 90% of maize genes. There are two major types of transposons: retrotransposons (which require RNA to be transcripted into DNA, using reverse transcriptase; they are the most common, making up over 98% of all transposons in the human genome) and DNA transposons (which do not require action from RNA). DNA transposons code for the protein transposase, which they use to remove and insert themselves along the genome. Autonomous transposons are capable of moving individually, but nonautonomous transposons need other transposons, since they don't code for transposase or reverse transcriptase on their own.

Transposons sometimes generate gene mutations. This can cause diseases, but can also be a way for an animal to respond to their environment, through adaptations.



There isn't a featured scientist this time. Instead:

Video of David Micklos and Susan Wessler of the Cold Spring Harbor Laboratory (where Barbara McClintock made her discoveries) explaining jumping genes:




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Sources:
http://www.dnaftb.org/32/
http://www.nature.com/scitable/topicpage/transposons-the-jumping-genes-518
http://www.sciencealert.com.au/news/20112908-22550.html
http://www.thefreedictionary.com/jumping+gene
http://waynesword.palomar.edu/transpos.htm

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Do you think the fact so many human genes can "jump" is a good thing or a bad thing?


-----The Golden Eagle

44 comments:

DeniseCovey_L_Aussie said...

Hi Golden. This is interesting. I hope that manipulating genes will one day lead to the elimination of some inherited diseases.

Denise

Rob-bear said...

Interesting presentation on genetics. As to whether jumping genes are good or bad, what different effects do they produce in humans?

shelly said...

Hey Golden:

Very interesting post! All I can say is this....um...yeah...as long as kissing and touching another human doesn't cause me a DNA rash it's all cool.

Question: WHat about the organic crops planted in between the GMO crops? There's some not good gene jumping going on there.

Humpty Dumpty said...

I took Biology in high school and they taught the basics of genetics, although during the week it was taught I was home with the measles! I took the Intro course in University but have never heard of transposons until now. I'm not all that sure whether 'jumping genes' are good or bad. It appears from your post that it is an adaptive thing to help the organism survive. As someone who never had an allergy as a kid to becoming allergic to dozens of things when I turned 40, I wonder if this is attributable to a jumping gene? Did one of these transposons leap onto my DNA, causing me to suddenly have all those allergies or was it a trait that lay dormant until something environmentally triggered it? I have no idea.

Jack said...

I'm getting lost in your gnome world! Very exciting read :)

MimiTabby said...

ah, this time I found "show comments" and after that i found a reply button.

Good nerdy theme!

Mimi Torchia Boothby Watercolors

Connie Keller said...

Loved this post!(When I was in college I worked as a cytogenetics technician.)

Stephen Tremp said...

Amazing post! Well, we've lived this long so jumping genes are not a species killer. I love the human genome (almost spelled gnome) project and sequencing. I did a paper on it in college.

Pat Hatt said...

I don't think they are such a bad thing, as humans are still alive and kicking, but I'm sure they have their down sides.

Matthew MacNish said...

I remember Mendel and his beans.

J. A. Bennett said...

This is awesome! I learned something new today :)

Jaye Robin Brown said...

I suppose it's good if it helps us adapt to changes in environment.

Carole Anne Carr said...

A fascinating thought, especially the idea of helping the organism to adapt and survive.

Morgan said...

I've been fascinated with genetics for several years now. What a great post---so glad I clicked on your link today :)

S. L. Hennessy said...

Not to trivialize what is obviously a very important part of the scientific field, but all I can think of when I hear the name is those jumping beans that bounce around in your hand. From now one, I want to call them jumping genes haha. I'll refrain.

Claire Hennessy said...

Wow, every time I visit your blog it feels like a science lesson!

M Pax said...

Wow. Great topic. I always found genetics interesting.

Joshua said...

I see Gregor Mendel and always think of Kafka's "Metamorphosis."

Alex J. Cavanaugh said...

If it results in disease, then that's bad.

Rusty Webb said...

I think that it's one of those things that solves one problem, but can cause others. I'd say the net result for us is that it's good. If I get a disease due to this then I'll change my opinion.

Nicole said...

So if the genes help living organisms adapt to their environment, I reckon this would mean that Chameleons would have these jumping genes, right? Even if this isn't so the post was interesting to read :)

It also reminds me that I missed an episode of "CSI: Miami" over the weekend -- totally unrelated, I know, but that's what was on my mind after reading this post.

~Nicole
Blog: The Madlab Post
@MadlabPost on Twitter

rch said...

Very interesting kernel of info ,-)

Nas Dean said...

Interesting information and word for your J!

J.C. Martin said...

As a keen scientist, I adore your A to Z series! Transposons are awesome genes!

J.C. Martin
A to Z Blogger

Carol Riggs said...

This sounds fascinating! It seems it would be a good talent for those genes to have, jumping around like that. :D

Jai Joshi said...

Well, if they help us survive then that must be a good thing. I'd be interested in seeing what happens if they worked to destroy though. How would that even work?

I love it when you post about scientific stuff like that. One day after watching a nova post you did, I spent hours on the pbs.org website!

Jai

Sandra Tyler said...

oh, goodness, refreshing and different in this challenge. I acrtually learned something new, thank you.

The Writing Goddess said...

Jumping jack fla-, uh, I mean genes. Love when "things" don't work the way we think they should - and then we discover a method to the madness.

mshatch said...

I'd have to know more about it to offer an intelligent answer. But I'd guess they couldn't be too bad since we're all still here.

Nick Wilford said...

So, is this basically how evolution works? The "bad" gene mutations would be the versions of animals that died out.

David P. King said...

Sweet science! I love it, eagle. Love it! :)

Susan Gourley/Kelley said...

I would guess in the grand design of thing it probably helps the species survive but it also explains how some rare congenital diseases appear.

The Beans said...

What a good and informative read!

-Barb the French Bean

Leigh Covington said...

This is awesome! I find genetics so fascinating. I don't know that I'm smart enough to do much with it, but I love learning about it. Always have. :)

Karen Elizabeth Brown said...

I thought this was an interesting post about genetics and jumping genes. As a writer, this gives me all kinds of ideas for a story I'm working on. Thanks!

Peggy Eddleman said...

Hm... I don't know. But I'm going to guess Good Thing. :)

ben268 said...

Really loved the read, I love genetics.

Robert Guthrie said...

Your aerial perspective makes my brain bigger. Um, or more neural pathways. THANKS!

Sarah Pearson said...

Hmm ... one of those things that gives with one hand and takes away with the other, I suspect!

Nate Wilson said...

Wow, interesting stuff. I had no idea some genes had managed to find a loophole in Mendelian genetics.

Although I must say, my brain kept wanting to read it as "transpoons," which I can only assume are microscopic forks that jump jeans to dress up as spoons. (My brain probably just likes my reading to have a combo of high-brow and low-brow elements. I wouldn't know; it never tells me anything.)

The Golden Eagle said...

Denise: That would be good!

Rob-bear: A variety of them. Some transposons can be beneficial or benign; others can cause dangerous mutations. I guess my question was what readers thought of their overall effect on life.

Shelly: Thank you!

Unlikely. :) I've never heard of anything causing a DNA rash!

I haven't heard about that before. There are negative gene mutations occurring in natural crops but not in the genetically-modified ones?

Humpty Dumpty: Hmm. That might have more to do with epigenetics; DNA that was coded because of circumstances your ancestors were in--or just immune system overreaction. Jumping genes, so far as I understand it, happen during early cell division and not later, as organisms first begin developing after the gametes fuse.

Jack: Glad you thought so. :) Thanks!

MimiTabby: Hooray!

Thank you.

Connie: Wow. That's really cool!

Stephen: Thanks. :)

The HGP was an amazing advance in science.

Pat: In the form of harmful mutations, unfortunately . . .

Matthew: He sure took care of a lot of beans.

J. A.: Great! :)

Jaye: Same here. I wonder how many transposons I have to thank for my current condition of good health.

Carole: It is! Barbara McKlintock was genius in coming up with her theory.

Morgan: Thank you so much!

S. L.: LOL. I thought of them when I was writing this post. :P

Claire: I hope it's as informative. :)

M: Thanks!

Joshua: I've never read it--but it's interesting how scientific names move into popular culture.

Alex: Sometimes it does. Other times, it's benign or even good for the organism.

Rusty: Hopefully you won't!

Nicole: Possibly; though I don't think the genes would be jumping around while the chameleon changed colors. :P

I've never watched CSI. What was "Miami" about?

Rch: Thank you!

Nas: Thanks.

J.C.: I'm glad you like my series!

They're certainly interesting ones.

Carol: LOL. Talented they are.

Jai: I don't think they could "work" to destroy--otherwise it would be direct genetic engineering.

Awesome. :) I love perusing the PBS site!

Sandra: You're welcome!

The Writing Goddess: It's a great moment. :)

Mshatch: Good point!

Nick: You got it.

David: I'm glad you enjoy the science! :)

Susan: I agree.

The Beans: Thank you!

Leigh: Thanks. And I hope you got the chance to learn something here! :)

Karen: Thanks!

You're very welcome for it.

Peggy: They are definitely capable of helping organisms!

Ben268: I'm so glad you liked it. I'm fascinated by the subject, too. :)

Robert: You're welcome! I aim to increase the neural pathways here. ;)

Sarah: Awful lot of things like that, aren't there?

Nate: It's not often someone pokes a hole in a major theory!

LOL. What a visual . . .

Deniz Bevan said...

Interesting! I hadn't heard of these. I only ever got as far as Mendel and his peas :-)

stuartnager said...

Is his hand glued to the desk? ;)

The Golden Eagle said...

Deniz: He did make some very important discoveries in genetics. :)

Stuart: LOL. Maybe . . .