[bionet.genome.arabidopsis] Genome Scanning

JGL@CORNELLA.CIT.CORNELL.EDU (Rob Last) (05/10/91)

People who are interested in ways to clone genes for which mutations are
available should have a look at 'Direct Molecular Identification of the
Mouse Pink-Eyed Unstable Mutation by Genome Scanning' by Brilliant etal.
in Science 252:566.  They were interested in cloning a gene for which
a very unstable allele was available (it turned out to be a tandem repeat).
They used a middle-repetitive probe to 'scan' the genome for regions that
were altered in the unstable mutant background compared with an isogenic
wild-type strain.  It worked.  It should work for homozygous viable
deficiencies, or possibly even for recessive lethals.  I am interested
in hearing any reactions to the technique- please reply to the Bboard.
Rob Last
Boyce Thompson Institute

cdt2@PO.CWRU.EDU (Christopher D. Town) (05/15/91)

I was very interested to read Rob Last's recent note on genome 
scanning. We have in fact been contemplating such an approach for
some time to try and get at the molecular basis of our radiation-
induced tumors which do not regenerate plants and defy conventional
genetic analysis. However, we have so far been unable to identify
suitably informative probe(s). i.e. ones present in high copy
number (1000+) and interspersed throughout the genome, as suggested
by the Brilliant article. We have one tumor line which repeatedly
throws off fast-growing variants which are shooty and have very
high cytokinin levels. Comparison of these variants with each other
and with the parent line (as well as with normal plant and with
other tumors) could be very informative.
I would be very pleased to receive suggestions os to possible
probes whwich might be suitable for this.
Many thanks,
Chris Town.