FIG. 5.

Activation of a heterologous 5′ SS by tra/tra-2. (A) Construct fruM+REwt containing wt tra/tra-2 repeat elements upstream of the male-specific fru 5′ SS and construct fruM+REmut containing mutant tra/tra-2 repeat elements upstream of the male-specific fru 5′ SS were transfected in the absence (−) or presence (+) of cotransfected tra/tra-2 as indicated above the RNase protection assay autoradiograph. RNase protection products derived from spliced and unspliced pre-mRNAs are indicated to the right of the autoradiograph and are as described in the legend to Fig. 5B. Lane M contains pSK+ DNA cut with HpaII. The positions of size markers (in nucleotides) are shown to the left of the autoradiograph. (B) Illustration of constructs fruM+REwt and fruM+REmut. The wt fru repeat region is indicated by three dashes, and the mutated fru repeat region is indicated by three asterisks. The repeat mutations in construct fruM+REmut are as in construct fruM+FREmut. For each construct, a specific RNase protection probe hybridizing across the splice sites was generated and is indicated by a horizontal bar below the constructs. RNase protection products corresponding to spliced and unspliced pre-mRNAs are shown below the constructs.