FIG. 5.
Noncanonical B/Da sites are needed for Sxlpe expression in P-element-transformed embryos. (A) Female and male embryos carrying wild-type −390 bp Sxlpe-lacZ fusions. Representative 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside (X-Gal)-stained XX embryos from strongly, moderately, and weakly expressing transformant lines are shown. XY embryos do not express Sxlpe. (B) Wild-type (wt) and mutant Sxlpe-lacZ transgenes stained for β-galactosidase activity. Numbers refer to the B/Da site mutations carried by the transgenes. None of the [1− 5− 6−], [2− 5− 6−], [4− 5− 6−], [1− 2−], or [1− 4−] lines expressed detectable β-galactosidase activity. Other mutant and wild-type lines exhibited a range of expression levels, but all were active. Representatives of moderate strength lines are shown.