The following information accompanied stocks donated to the Bloomington Stock Center by Balaji Iyengar, Hamilton Health Sciences.
A P element inserted in the middle of the first CG6051 intron expresses GAL4 in the late pupal wing blade. Because this expression pattern is similar to that of blade runner (blr/CG7447/slowdown), Bala has named this gene blade runner 2 (blr2) and the insertion allele blr21. The allele produces muscle degeneration and larval lethality when homozygous.
The P element construct inserted in blr2, P{UAS-DD-GAL4.VP16.I} consists of the coding sequence of the FKBP12 destabilization domain (described in Banaszynski et al. (2006) "A Rapid, Reversible, and Tunable Method to Regulate Protein Function in Living Cells Using Synthetic Small Molecules", Cell 126: 995-1004) fused to the 5' end of a GAL4.VP16 fusion sequence. This sequence was cloned downstream of UAS in a Casper-based vector. Bala's intention in building this construct was to express a GAL4 whose degradation could be controlled chemically by the Shield-1 small molecule inhibitor. This particular insertion does not behave as predicted with respect to UAS-induced expression, nor does the destabilization domain appear effective, but the striking recessive muscle degeneration phenotype makes it interesting nonetheless. When combined with a UAS-GFP construct, the insertion also produces fluorescence in larval skeletal muscles and trachea, presumably reflecting the enhancer activity of blr2 regulatory sequences.
It is not known if P{UAS-DD-GAL4.VP16.I} shows the expected UAS-inducible expression in other insertion sites.
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Kevin Cook, Ph.D.
Bloomington Drosophila Stock Center
http://flystocks.bio.indiana.edu