Figure 5.

dom modifier screen. (E) shows the recombinant chromosome C96-domR containing the C96-GAL4 and UAS-domR transgenes. It produces the weak wing nicking phenotype shown in (F; penetrance of ∼57%). (A and B) Controls demonstrating that the wing phenotype is affected by changes in the level of wild-type Dom expression, either through GAL4 coexpression of a wild-type Dom construct [UAS-DomB (A)] or through a LOF allele [dom¹ (B)], as described in the text. The EP screen involves testing individual EP insertion chromosomes as transheterozygotes with C96-domR (E). In these genotypes, C96-GAL4 can drive both UAS-domR and a random sequence if the EP insertion is oriented appropriately. The EP element also generates LOF alleles. Wing modifications, such as enhancement [EP558 (C), 88% penetrance and increased severity] or suppression [EP1202 (D), 0% penetrance, total suppression] are scored.