Colleagues,
I recently inquired if anyone knew about selective methods to
isolate yeast transformants that have lost plasmids carrying auxotrophic
markers other than URA3. Specifically, loss of TRP1, HIS3, and LEU2.
I thank Preston Garrison, Peter J. Punt, Charles N. Cole and John
Simon for responding. It was pointed out that alpha amino adipate selects
for lys2 and lys5 mutants, but counter-selective reagents specific for the
other markers apparently are unknown.
We are testing a general and simple method for selecting for loss
of plasmids carrying any auxotrophic marker. In order to assess the
generality of the approach, I need a few cloned yeast genes in plasmids
that carry HIS3, TRP1, and LEU2, and the corresponding mutants. Any gene
will work, but those in which mutations confer an easily scorable phenotype
are preferred.
I would appreciate any offers and will share our results in this format.
Sincerely,
Alan T. Bakalinsky, Ph.D.
Department of Food Science and Technology,
Wiegand Hall, Oregon State University
Corvallis, OR 97331-6602
Internet: bakalina at bcc.orst.edu
Phone: (503) 737-6510
FAX: (503) 737-1877
