Cambrian Explosion

Posted by Martin C. Martin-2 on
URL: http://friam.383.s1.nabble.com/Cambrian-Explosion-tp521557p521568.html

The book "The Art of Genes" talks about a lot of this stuff, including
Hox and momeobox genes.  It's a book for the educated lay person,
doesn't requre a background in biology.

- Martin

Jochen Fromm wrote:

> I have heard of Hox genes before, but not in the context
> of the Cambrian Explosion. Looks like it is associated with
> the evolution of Hox genes. Wikipedia says Hox and
> "homeobox" genes are closely related to the body plan. They
> are labels and markers, i.e. they assign the right identity
> to particular body regions along the body axis (individual
> hox genes are activated at different positions), but they
> also control the development. This means they represent and
> control the structure of the body at the same time, just
> like the emotions (as we know from Psychology) signal the
> state of the body and control the body at same time.
> http://en.wikipedia.org/wiki/Homeobox
>
> Does this mean that the code for embryonic development is
> related to "meta" genes (transcription factors which
> typically switch on cascades of other genes) ? Interesting.
> The hox genes are therefore perhaps a code in a code ?
> Changes in Hox gene number results in different phyla
> and body plans, changes in Hox gene expression in slightly
> modulated body plans with different numbers of segments, and
> subtle changes in the details of a Hox transcription
> pattern results in modified segments, see the following
> article about "Shaping animal body plans in development
> and evolution by modulation of Hox expression patterns"
> http://www3.interscience.wiley.com/cgi-bin/abstract/34221
> http://wwworm.biology.uh.edu/evodevo/lecture18/gellon98.pdf
>
> -J.
>
>
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