SJ Gould on genome

Charles Brown CharlesB at CNCL.ci.detroit.mi.us
Mon Feb 26 07:28:03 PST 2001



>>> pvh at egenetics.com 02/26/01 02:54AM >>>
On Fri, Feb 23, 2001 at 09:16:50AM -0500, Charles Brown wrote:
> CB: I see.
>
> So, the retro virus proteins send a message to the host cell DNA telling
> it to print out retro virus proteins, violating the part of the dogma as
> formulated by Crick which says no protein to nucleic acid messages ?
>
> However, the message to the host cell DNA from the retrovirus protein
> does not change the host cell DNA itself. That would be required for
> violating the dogma against Inheritance of Acquired Characteristics. It
> might even have to be that the protein changes gonadal cells in a way
> that directly impacts the way the next generation of offspring respond
> to this specific protein and virus, this specific aspect of the
> environment to violate the "no IAC" dogma?

Peter: No - you've got this wrong - the retroviral nucleic acid is spliced into the DNA of the host cell - i.e. its genes appear as genes in the host cell. Then new viral proteins are synthesized from these genes, since the host cell's protein creation machinery can't treats the 'invader' genes the same as 'its own' genes. So the CD is clearly violated.

(((((((((

CB: If it is retroviral nucleic acid that is spliced into the host DNA , that seems to be a message from nucleic acid "to" nucleic acid, not from a protein to a nulceic acid. At first , I thought you said there was a message from the virus protein to the host cell DNA, which would seem to violate the CD ( as quoted earlier from Crick).

Anyway, if I understand you above you are saying the CD is violated, but by CD you don't mean the rule against Inheritance of Acquired Characteristics, do you ?

I may not have been clear in the way I said it immediately above, but I was trying to articulate the difference between the CD and the rule against Inheritance of Acquired Characteristics. I was taking your statement that the CD is violated, and then trying to differentiate that from the rule against ( dogma ?) Inheritance of Acquired Characteristics (no IAC).

But I see below that you are saying the IAC dogma is violated. So, are we back to Lysenko as not such a nut afterall , since his big sin was claiming that it was possible to induce plants to inherit acquired characeristics ?


>
> CB:I wonder if the difference between the central dogma as stated by Crick
> and violation of Inheritance of Acquired Characteristics dogma might be
> this as I just said.

Peter: Well... in so far as retrovirii are probably going to be used to implement 'gene therapies', I guess you could say that they would play a role in the inheritance of acquired characteristics. To clarify - as I understand it, one approach in gene therapy is to take a retrovirus, remove its nucleic acid and replace with a 'fixed' gene (e.g. the correct form of the gene which, if mutated, leads to cystic fibrosis). Then inject the tailored retrovirus into a human, and let it splice the 'fixed' gene into their genome - the result is that the genetic disease that that human had is cured. Of course, the cure is inherited, along with the other genes in the human.

(((((((((((

CB: OK so the rule against inheritance of acquired characteristics, anti-LaMarckianism, is not so hardnosed So, although Lysenko may not have had a gene therapy technique, his aim was not as off the wall as claimed by some ?

(((((((((

CB: This is, however, different to how I normally have understood the Lamarckian 'inheritence of acquired characteristics' concept. As I've understood that, that is about some response to the environment being inherited. Nothing I know about biology indicates that there is a communications channel which can channel information about the responses to the environment back into the genome of an organisation - that would be a phenotype to genotype information transfer of a kind I'm not familiar with.

(((((((((((

CB: So, as you understand it there is a difference between what we have been referring to as the Central Dogma and the dogma against inheritance of acquired characteristics ? But that difference is not the same way as I stated it last post ?

If the viruses are used by humans to do this, might not there be some unknown avenue that nature uses ?

I guess I am saying that what you have explained to me about the retroviruses seems to make it more plausible that nature , without human help, might have a way of using the retrovirus mechanism you talk about along with some other mechanism not discovered. Certainly, at the time the dogma against inheritance of acquired characteristics arose before the retrovirus process was known.


>
> However, we are talking retroviruses. No violation of either dogma by
> evidence from human genome project ,no ?

Yeah - as I said, I don't think the HGP should have provoked the discussion it did (from Gould, etc.).


> (((((((((((
>
> CB: I hate capitialism.
>
> I know what I was thinking, but didn't say. Does the sequencing of the
> _human_ genome give some potential insight as to where the viruses are
> plugging into the human host cell DNA or RNA to replicate, another point
> at which the viruses process might be stopped ? This would be something
> from the recent news and project that might help the work of the type
> you are doing.
>
Yep, the HGP is a step towards understanding the 'proteome' - i.e. the complement of proteins in the human body. Understanding that better will give us more of a clue about the human 'targets' the the virii use. Once we've got human figured out, understanding how virii (which are genetically far simpler) interact with human molecular biology will be much easier. Full understanding of human molecular biology is a long way off, though. Some scientists are comparing our position today to that of the viewers of the first decent disections - we know what's there, and now we can start trying to figure out what it means.

Peter P.S. some people are proposing a 'human proteome project' - a large scale effort to map out the structure of all human proteins. That would be a good idea, in my mind.

((((((((((

CB: Thanks muchly for sharing your expertise.

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