Received: by alpheratz.cpm.aca.mmu.ac.uk id XAA17656 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Tue, 13 Feb 2001 23:40:21 GMT X-Originating-IP: [209.240.221.102] From: "Scott Chase" <ecphoric@hotmail.com> To: memetics@mmu.ac.uk Subject: Re: Human Genome Date: Tue, 13 Feb 2001 18:37:50 -0500 Content-Type: text/plain; format=flowed Message-ID: <F47FYgx7YbNcvHjtQab0001aba4@hotmail.com> X-OriginalArrivalTime: 13 Feb 2001 23:37:50.0421 (UTC) FILETIME=[FA4D1850:01C09615] Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
>From: <joedees@bellsouth.net>
>Reply-To: memetics@mmu.ac.uk
>To: memetics@mmu.ac.uk
>Subject: Re: Human Genome
>Date: Tue, 13 Feb 2001 00:01:48 -0600
>
>On 13 Feb 2001, at 11:08, Dr Able Lawrence wrote:
>
>That's 30,000.
> >
> > Hi All,
> > Genome report (only 3000 genes) is not really surprising at
> > all if
> > we understand the implications of the recently discovered complexities
> > in gene expression regulation The transcription factors are huge multi
> > subunit complexes with countless interactions amongst them. The
> > permutation and combination possible for interactions amongst
> > transcription factors is realy mind boggling. There is more to
> > genetics than mere genes and DNA sequences.
> > The real implication of the new finding is that one gene- one
> > function hypothesis is dead. Now we know that a single gene can
> > produce myriad proteins like the immunoglobuin or T cell receptor or
> > neural adhesion molecules involved in the complex wiring of the
> > nervous system. On the contrary multiple genes are required for
> > functional units (multi subunit complexes) involved in such vital
> > functions as regulation of gene expression or respiration or protein
> > synthesis.
> > A lot of the complexity in higher organism is probably at the
> > level
> > of gene-gene interactions and the complex cascading and epigenetic
> > effects on gene expression.
> > To emphasize the point further, all our cells have the same DNA
> > sequence (well almost) but are morphologically and functionally
> > diverse.
> > So it is not necessary to have different sets of genes but more
> > fine
> > tuned interactions to create us humans.
> > As I pointed out earlier that smple minor variations in gene
> > expressions can have profound morphological implications. So the gene
> > regulating embryogenesis (Hox genes) are highly conserved vertically
> > in the evolutionary ladder (ladder itself is an anthropocentric view
> > and other organisms can object!)
> > Throughout evolution new functions have rarely ever come about by
> > inventing new genes (it takes too much directed ingenuity for that,
> > may be only Lamarck or biotechnologists a few decades down the line
> > can only do it) but by making new use or modifying old genes. Once
> > useful but rudimentary function is discovered for an old gene,
> > variation and evolution (and duplication if the old gene already has
> > an indispensable function) would be favoured and would arise in due
> > course of time. Duplication of genes in malignant clones in the body
> > is a case in point.
> > It would be ridiculous to say that the multidrug resistance gene in
> > human malignancy had the same function before that begins to get
> > favoured by surviving tumour cells.
> > We must view genes as dynamically interacting
> > information
> > and also should not forget that the genes get their properties through
> > the proteins they encode (with all the complexities of protein
> > chemistry and protein protein interaction)
> >
> > Anthropocentrism is alive only in Christian theology!!
> >
>
>
The number may be off, but the jist about gene for this and that being dead
is important. With cooperation within co-adapted gene complexes being a big
consideration, it looks like they threw their innate selfishness out the
window long ago and opted to subserve the generation of a body plan and the
needs of the organis^h^h^h^ehicle. Genes operate in a context where
cell-cell interaction and the molecular interplay at the surface are
important.
Another point is that our cells possess the same genome, but during
differentiation and specialization, they express different subsets of the
genome or express various genes to different degrees. IIRC methylation is an
important means to shutting genes up (ie- regulation).
I'll pretend I didn't see the part about ladders.
BTW Joe did you miss my post to Robin about P.E.T. recently? What did you
mean by the release of isotopes?
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