Fig. 6. TAGteam sequences affect the timing and penetrance of transcription from Sxl_Pe. (A,C) In situ hybridization to lacZ RNA from a cycle 14 embryo carrying, respectively, the wild-type or the mutTAGteam 1.4-kb Sxl_Pe-lacZ reporter transgene described in Fig. 5. (B,D) Nuclear dots of lacZ RNA hybridization in a cycle 13 embryo of the genotype as in A or C, respectively, co-stained for DNA (DAPI) to reveal nuclei. (E) Expression measured as the average number of dot-containing nuclei per presumed female embryo (n30 embryos per cycle per transgene). Arrows indicate onset of transcription (first cycle 5% expressing nuclei). Dot analysis was performed on a single wild-type and TAGteam mutant transgene line, each determined to be representative based upon ß-galactosidase staining. Scale bars: A,C, 50 µm; B,D, 20 µm.