question about gene evolution

[Brian Foley]

sb9e (sb9e at faraday.clas.virginia.edu) wrote:
:      I have a couple of probably naive questions about the evolution of
: gene structure in animals. Many homologous genes contain more exons and
: thus are more fragmented in higher mammals than in lower animals.

	I'm not sure that this is true.  Prokaryotes have few introns 
compared to eukaryotes, but I have never found that mammals have more 
introns than other vertebrates or even invertebrates.  

: First, is this a general tendency? Second, is this considered a result
: of fragmentation of the gene during evolution or rather a structural
: simplification in lower organisms? 

	Reviews of this can be found in:
		Nature Volume 271 page 501 "Why genes in pieces?" 
		by Walter Gilbert 

		Science Volume 250, pages 1377 to 1382 "How big is the 
		Universe of Exons?" by Robert Dorit, Lloyd Schoenbach
		and Walter Gilbert

:      I would be very grateful for any suggestion or indication of
: references on this subject. Thank you,

:                             Serge Birman
:                             sb9e at virginia.edu

--
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*  Brian Foley               *     If we knew what we were doing   *
*  Molecular Genetics Dept.  *     it wouldn't be called research  *
*  University of Vermont     *                                     *
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