Dominant effects of crc1 on the phenotypes of EcR-B1-F645A expression.

All flies contained, in addition to the indicated crc genotype, one copy of UAS-EcR-B1-F645A and one copy of the indicated driver. Quantitative data represent % viability to adult eclosion for the indicated genotype; the nature of the lethality in each case is described elsewhere [5]. Effects of EcR-B1-F645A in the slbo domain were assessed qualitatively by observing the tendency of eggs laid by an affected female to collapse. Each datum was produced by crossing a driver stock to either UAS-EcR-B1-F645A/CyO (crc+/crc+) or UAS-EcR-B1-F645A crc1/CyO (crc1/crc+). Survival was determined by comparing the number of adults recovered which carry the UAS-EcR-B1-F645A-containing chromosome with the number of adults carrying the CyO balancer; the number in parentheses indicates the number of EcR-B1-F645A-expressing adults recovered. In a control experiment to determine the relative strength of transgene expression in each domain, the Gal4 drivers were crossed to UAS-nuclear-GFP (FBti0012492), the tissues were fixed in 4% paraformaldehyde and washed, and the intensity of direct GFP fluorescence in single confocal sections (signal - background) was quantified. The mean intensities of GFP fluorescence were: dpp (FBti0002123) 71.6+/−9.6, GMR (FBti0002994) 59.3+/−6.3, slbo (FBti0023075) 50.9+/−9.4, Eip (FBtp0016770) 30.6+/−4.3, Lsp2 (FBti0018531) 25.8+/−4.8 (+/− SEM, n = 6). Thus, the intensity of driver expression was not correlated with the ability to enhance the EcR dominant negative phenotype.