DNA data - how useful is it realy?

Keith Robison robison at nucleus.harvard.edu
Thu Aug 31 22:45:42 EST 1995


Ludvig Mortberg (Agneta.Guillemot at historia.umu.se) wrote:
: Sequencing of genes is an industry today. I don't know how many base
: pairs have been sequenced in the world, but they must lie in the range
: of hundreds of millions. But what can realy be learnt from just
: studying a DNA sequence? You see enhancers, promotors, introns and
: exons stop codons etc. You may be able to conclude that the
: polypeptide chain encoded by the gene transverses a membrane. 

Once you have the complete sequence, you can say what is
and _is not_ there.  You can rapidly map genes given a little
bit of sequence, and rapidly find candidate genes given a map
region.  A complete sequence is the ultimate genomic map!

: I suspect that much research today where people sequence genes just
: for the sake of it, only confirms what we already know about molecular
: biology of genes. Maybe the large amount of sequencing made draws
: attention from more important fields of biology, that would require
: more research.

Au contraire -- sequencing _complements_ the other fields of
biology.  

: The big issue in biology today, as I see it, is how morphogenesis and
: differentiation takes place. We know today how curly hair is inherited
: in Drosophila, maybe we have even cloned the gene, but how does it
: become a curly hair (or a straight one) no body knows.

And one of the huge trends in biology is methods which generate
lots of short sequence tags tied to experimental data -- 
transposon tagging, differential display, peptide sequencing, etc.
With such methods (and large amounts of sequencing) one can
instantly map a gene, pick candidate genes for a trait, identify
the protein responsible for an effect, etc -- all by database
search (in contrast to conventional mapping & full-gene cloning
efforts).  In addition, all those sequences let you jump
quickly from one experimental system to another.

: There's just too much sequencing in the world!

I (of course) would disagree -- sequencing is not at odds with
the sort of study you describe -- rather, it is a highly useful
infrastructure supporting such efforts.  And in the case of
experimentally-difficult species (such as many pathogens),
the sequencing makes experimentation infinitely easier by
allowing knowledge from more approachable systems to be
extrapolated onto the difficult system.

Take a look at how geneticists and biochemists are taking
advantage of all those sequences, and then come back
and complain about "too much sequencing".

Keith Robison
Harvard University
Department of Cellular and Developmental Biology
Department of Genetics / HHMI

robison at mito.harvard.edu 













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