Retrovirus

[The Peon]

My question is, how do geneticists know that particular sequence of DNA is caused by a retrovirus rather than a normal inherited gene sequence? I read an article that 8% of our genome is retrovirus inscription, and that we share 16 known retrovirus inscriptions in our DNA with Chimps. I was curious as to how scientists know the difference of normal DNA and Retroviral?

[Mr Skeptic]

Well one group of scientists recreated one of the retroviruses by putting together the fragments, and it could infect cells.

 

But the more usual way is to compare the sequences to other known sequences and see if they match.

[The Peon]

Well one group of scientists recreated one of the retroviruses by putting together the fragments, and it could infect cells.

 

But the more usual way is to compare the sequences to other known sequences and see if they match.

 

I assume you mean known retro virus sequences that they are comparing the human DNA to? So technically if that were true, some DNA sequences in humans could in fact be retrovirus that are now "extinct?" and we assume they are normal inherited DNA sequences? Or am I missing something here? I am a bit confused sorry.

 

 

*edited for slight clarification

Edited October 25, 2010 by The Peon

[Mr Skeptic]

Correct. In fact, the virus they resurrected would have had to be an extinct strain (that's even more specific than species, but species is an odd concept for things like viruses that don't reproduce sexually. I don't know if it was extinct at a higher taxonomic level though).

 

Here's a couple articles about this:

http://genome.cshlp....ss/Herv_K.xhtml

news.sciencemag.org/sciencenow/2006/11/01-04.html

 

Note that they had to use multiple copies to deduce the original, since any one copy would have been full of mutations.

[The Peon]

Correct. In fact, the virus they resurrected would have had to be an extinct strain (that's even more specific than species, but species is an odd concept for things like viruses that don't reproduce sexually. I don't know if it was extinct at a higher taxonomic level though).

 

Here's a couple articles about this:

http://genome.cshlp....ss/Herv_K.xhtml

news.sciencemag.org/sciencenow/2006/11/01-04.html

 

Note that they had to use multiple copies to deduce the original, since any one copy would have been full of mutations.

 

 

Thank you very much for the answer. It's greatly appreciated *thumbs up*

[CharonY]

There also a number of patterns that emerge due to recombination with viral sequences, and also the detection of genes with virus specific functions would be revealing.

[Darwinsbulldog]

Some parts of the human [and of course other organism] genomes possess endogenous endoviruses...genes sequences very similar to retroviruses in the wild. It might help to check out a paper like this one:-

 

Ryan, F. P. (2004). "Human endogenous retroviruses in health and disease: a symbiotic perspective." J R Soc Med 97(12): 560-565.

[vordhosbn]

Is it possible (and probable), that from DNA, that did not originate from retro-viruses, a sequence can be extracted, that can function as one?

 

Way back, thinking about DNA, I always made analogy with source code... but now I am beginning to think that may not be good comparison...

Most modern computer languages are very context-specific and non-heuristic oriented.

Edited October 26, 2010 by vordhosbn