Mysterious Snippets Of DNA Withstand Eons Of Evolution

Mysterious Snippets Of DNA Withstand Eons Of Evolution

www.sciencedaily.com

ScienceDaily (Oct. 7, 2008) — Small stretches of seemingly useless DNA harbor a big secret, say researchers at the Stanford University School of Medicine. There's one problem: We don't know what it is. Although individual laboratory animals appear to live happily when these genetic ciphers are deleted, these snippets have been highly conserved throughout evolution.

"The true function of these regions remains a mystery, but it's clear that the genome really does need and use them," said Gill Bejerano, PhD, assistant professor of developmental biology and of computer science. In fact, these so-called "ultraconserved" regions are about 300 times less likely than other regions of the genome to be lost during mammalian evolution, according to research from Bejerano and graduate student Cory McLean.

Although some of the ultraconserved regions, which were first identified by Bejerano in 2004, are involved in the regulation of the expression of neighboring genes, previous research has shown that mice missing each of four regions seem perfectly normal.

"It's very surprising that none of the four has any observable phenotype," said Bejerano. "In some ways it just doesn't make sense."

(visit the link for the full news article)



[edit on 8-10-2008 by grover]

I hear strains of the X-Files theme playing in my head.

I really don't know what to say about this... my understanding of DNA (other than what it is and does) is limited but it is my understanding that if something is no longer of any use biologically then it is ultimately discarded (they have even found lately that the appendix actually serves a purpose) so these snippets must do or record something but what?

www.sciencedaily.com
(visit the link for the full news article)

Junk DNA has been known about for ages, not sure why this has resurfaced in the news now?

One interesting possible explanation is that it is an archive of past genetic information held in storage as backup should it prove evolutionarily advantagous to have a certain mutation in the future.


[edit on 8-10-2008 by Man_Versus_AntiMan]

reply to post by Man_Versus_AntiMan


But is it really junk? I mean its there so it either had to or does serve some purpose.

reply to post by grover


Well yeah, if the storage theory is correct then it did serve some purpose in our past but doesnt now, and is just being held in case we need the genes in the future.

There is no evidence for that its just speculation, but it could explain why these lab mice can seemingly function normally when these regions are removed.

A really far out speculation would be that this mechanism could have aided dolphins to re develop flippers and dorsal fins from their land based like ancestors, because they had kept the genes in storage. Just a thought

Another explanation is that the stuff may have some enzymatic function, buts thats not nearly as intersting as carrying monkey and fish genes around with you.

"We don't know what it is, what it does, but we're absolutely sure it is worthless and can be removed!"

Would anyone ride in a car or airplane if the mechanic had that attitude?

I would guess the mice where the parts of DNA have been removed have a higher change to get cancer also the chances of a negative SNP to occur would be higher.

Posted this one yesterday here for other discussion.

www.abovetopsecret.com...'

reply to post by sir_chancealot


Actually I've had mechanics like that.