Re: mitochondrial DNA (was Kerala on CBC)

Jaro,

According to one of the references below, mitochondria are essentially bacteria that got stuck inside bigger cells. I would think that a study of radiation effects on mitochondrial DNA, would be as relevant to human nuclear DNA as a study of radiation effects on any other bacteria. (I'll put it on-list.)

Kai

----- Original Message -----

From: Franta, Jaroslav

To: 'Kai Kaletsch' ; Jacobus, John (NIH/OD/ORS)

Sent: Thursday, November 14, 2002 7:35 AM

Subject: RE: mitochondrial DNA (was Kerala on CBC)

That question has occurred to me too: i.e. are "repair mechanisms identical between mitochondrial DNA and nuclear DNA?"

If mitochondrial DNA has NO repair mechanisms, the conclusions would of course be way off !

Might be worth repeating it "on-list."

Jaro

-----Original Message-----
From: Kai Kaletsch [mailto:eic@shaw.ca]
Sent: Wednesday November 13, 2002 9:09 PM
To: Jacobus, John (NIH/OD/ORS); Franta, Jaroslav
Subject: Re: mitochondrial DNA (was Kerala on CBC)

(off list)

Thanks John,

When Forster says:

"...because we looked at a region of our genome which does not code for a gene, so it does not create any visible effects, whether beneficial or adverse, but there's no reason to suppose that mutations here of course are restricted to such non-coding regions. We have to assume that other genes, like for example, cancer genes, will be equally affected by these mutations."

Does he mean that cancer genes are carried on mitochondrial DNA or does he mean damage and repair mechanisms are identical between mitochondrial DNA and nuclear DNA? To my (very limited) understanding of biology, both are wrong.

Radiation effects on mitochondrial DNA is probably a valid research field on its own. But to leap from a study like that to some statement about dose limits crosses the line between science and ....

Good night,

Kai

----- Original Message -----

From: Jacobus, John (NIH/OD/ORS)

To: 'Kai Kaletsch' ; Franta, Jaroslav ; Radsafe (E-mail)

Sent: Wednesday, November 13, 2002 3:35 PM

Subject: RE: mitochondrial DNA (was Kerala on CBC)

Kai,

Try

http://tilapia.unh.edu/WWWPages/mtdna/mtdna.html

http://www.mitotyping.com/dna.htm

http://www.columbia.edu/cu/21stC/issue-1.3/dna-mitoch.html

I am not sure if they answer your specific questions, but should give some useful background information, particularly the last one.

-- John

-----Original Message-----
From: Kai Kaletsch [mailto:eic@shaw.ca]
Sent: Wednesday, November 13, 2002 2:40 PM
To: Franta, Jaroslav; Radsafe (E-mail)
Subject: mitochondrial DNA (was Kerala on CBC)

Can someone give me a bit of info on mitochondrial DNA? I know what researchers use it for, but what does the body use it for? Is a mutation in mitochondrial DNA likely to have an effect on the viability of the organism? I thought is was quite separate from our regular DNA. Would the repair mechanisms for mitochondrial DNA be the same as for regular DNA?

Thanks in advance,

Kai

http://www.eic.nu

and http://www.gammawatch.com/

From: Franta, Jaroslav

To: Radsafe (E-mail)

....

. We look at a part of our DNA which is handed down entirely through the maternal lineage, through the mothers. And this is called mitochondrial DNA, or MT DNA for short. And we looked at this DNA because it's very easy to trace within families....