Fig. 1. Sequence and splice variants of pax8. (A) The complete sequence of the pax8 variant 3 transcript. Exons predicted by comparison to genomic sequence are indicated above the sequence. The transcription start site, preceded by a TATAA box, begins with exon 1a. Exon 1 is contiguous with genomic DNA sequence, but has been subdivided into exons 1a, 1b, and 1c to indicate that the splice variants shown in Fig. 1B contain different parts of exon 1. The arrow indicates the putative start codon used in variant 1 transcripts. The star indicates that some transcripts use an alternate splice donor site that extends exon 9 by 33 bp (sequence not shown). The canonical Paired domain and predicted transactivation and inhibitory domains are indicated below the sequence. Polyadenylation (polyA) sites are underlined in purple; the majority of transcripts (52/54) use the first polyA site. (B) A schematic representation (not to scale) of the splice variants observed in pax8 transcripts. The variant name (e.g. 1.1, 1.2), total number of representative transcripts out of 54 total sequenced, and percentage abundance are indicated after each schematic transcript. The unlabeled box between exon 9 and exon 10 in variants 1.4 and 1.5 indicates an additional 11 amino acid insert (see also Fig. 1A) resulting from the use of an alternate splice donor site. The predicted coding sequence for variants 2 and 3 begins with the start codon in exon 1c; all variant 1 transcripts use the start codon in exon 2 indicated by the arrow in Fig. 1A.