Fig. 1. Nos reporter transgenes for ectopic expression. (A) The nos-coding region (shaded) and 5'UTR sequences (hatched) were fused to yeast UAS sequences to permit transcriptional activation of nos by GAL4. In the UAS-nos-tub3'UTR transgene (top), the nos 3'UTR is replaced by the -tubulin 3'UTR (open box). In the UAS-nos-tub:nos+2 transgene (bottom), the -tubulin 3'UTR sequences contain an insertion of the nos 3'UTR +2 element (black box), which includes the nos TCE and an adjacent region with weak translational repression function. The UAS-nos-tub:TCE transgene (not shown), which carries an insertion of the TCE alone, behaves similarly. (B) Transgenes are identical to those in A, except for the presence of a stop codon mutation (*) in the nos-coding region.