Human genomic DNA sequence alignment with mesothelin transcript variants. Selected portions of human genome sequences corresponding to the mesothelin gene (AL031258) were aligned with corresponding sequences of reported mesothelin transcript variants. (-) represents sequence gaps for optimal alignment. A. The 5'-ends of mesothelin transcript variants 1 and 2 (tr1, NM_005823; tr2, NM_013404) aligned with the genomic DNA sequence. Lower case letters represent presumed untranslated nucleotide sequences. B. Nucleotide sequence at the exon 13 5'-boundary using the same reference database sequences as in (A). Lower case letters in the genomic sequence indicate presumed introns for transcript variant 1. Splice acceptor sites potentially utilized by transcript variants 1 and 2 are underlined, and the arrowhead indicates a third splice acceptor detected by sequence analysis in this study. C. Genomic sequence for the intron 16 region are aligned with sequences for transcript variants 1 (tr1, NM_005823) and 3 (tr3, AF180951). Lower case letters represent nucleotides presumed to be untranslated for tr1. Expected amino acid sequences are shown above each transcript, highlighting the intron 16 insert and reading frame shift predicted for tr3.