heat-shocked, synthesis of FLP recombinase was in- 
duced, catalyzing recombination between FRTs. 
This recombination caused loss of the white gene, 
seen somatically as white patches on a pigmented 
background in the eye. Less frequently it causes 
gain of a copy of the white gene, in tandem with 
the first, seen as patches of darker pigmentation. 
The frequency of loss and gain varies with the se- 
verity of the heat shock used to induce FLP synthe- 
sis. The patterns of somatic mosaicism produced by 
the heat shock are characteristic of the develop- 
PUBLICATIONS 
mental stage at which it is applied. The recombi- 
nase is also active in the germline, producing white- 
eyed progeny carrying a single FRT (instead of 
white flanked by FRTs) and dark red-eyed progeny 
carrying two tandem copies of white. This system 
has a wide variety of potential applications for the 
genetic analysis of Drosophila and other organisms. 
Dr. Lindquist is also Professor of Molecular 
Genetics and Cell Biology at The University of 
Chicago. 
Articles 
Borkovich, K.A., Farrelly, F.W, Finkelstein, D.B., Taulien, J., and Lindquist, S. 1989. hsp82 is an essential pro- 
tein that is required by cells in higher concentrations for growth at higher temperatures. Mol Cell Biol 
9:3919-3930. 
Lindquist, S. , and Craig, E.A. 1988. The heat-shock proteins. Annu Rev Genet 22:6^1-617 . 
Rossi, J.M., and Lindquist, S. 1989. The intracellular location of yeast heat-shock protein 26 varies with me- 
tabolism. /Ce7757o7l08^25-439. 
Yost, H.J., and Lindquist, S. 1988. Translation of unspliced transcripts after heat shock. Science 242:1544- 
1548. 
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