FIG. 2.

RNase protection analysis of unc-52 transcripts in smu-2 mutants. (A) Depiction of the unc-52 probe used for RNase protection experiments. The complete probe transcribed from the T7 promoter and including vector sequences is 338 nt long and contains 219 nt of exon 16 and 11 nt of exon 18. Probe lengths protected by different splice forms are indicated. (B) Data from three independent RNase protection experiments from unc-52 and smu-2 unc-52 larval RNA. The data from the 219- and 220-nt protected fragments, representing 16-17 and 16-19 splice forms, were grouped together because the fragments do not reliably distinguish these transcripts. The mean ratios for 16-18/(16-17 plus 16-19) transcripts was 0.545 ± 0.032 for unc-52 larvae and were 1.157 ± 0.156 for smu-2 unc-52 larvae; these values were found to be significantly different in a paired t test (P = 0.041). Mean ratios for 16-18/ama-1 transcripts were 0.323 ± 0.0002 for unc-52 animals and 0.667 ± 0.065 for smu-2 unc-52 animals; these values were also found to be significantly different in a paired t test (P = 0.034). These data indicate that there is about a twofold increase in the abundance of the 16-18 splice form in smu-2 mutants.