Fig. 5. Ppa-pax-3 transcript levels are reduced in Ppa-lin-39 mutants compared with P. pacificus wild type. (A) PCR amplification and sequence analysis of Ppa-pax-3 cDNA clones reveals the existence of two isoforms. The Ppa-pax-3b isoform misses the N-terminal PAI subdomain of the paired domain (PD), but contains the RED subdomain, the octapeptide and the homeodomain (HD). Both isoforms are trans-spliced to an SL1 leader sequence. (B) Ppa-pax-3 transcript levels in staged P. pacificus wild-type animals. Transcript levels are given as arbitrary concentration unit ratios between Ppa-pax-3 and Ppa-ß-tubulin as an internal standard. RNA was prepared from 100 animals and experiments were carried out in triplicate. Error bars represent standard deviations. (C) Relative Ppa-lin-39 transcript levels in wild-type and Ppa-pax-3(tu214) mutant animals. Ppa-lin-39 transcript levels are unchanged. (D) Relative Ppa-pax-3 transcript levels in wild-type and Ppa-lin-39(tu29) mutant animals. Ppa-pax-3 transcript levels are decreased from approximately 40 to 5 concentration units.