Illustrative examples of inferred tandem donors. White boxes denote exon and lines intron nucleotides; exon numbers (E#) corresponded to 5'-to-3' enumerated REFSEQ-annotations, the splice site score as measured by MAXENTSCAN, and the transcript coverage of the proximal and distal donor site corresponded to the number of aligned sequences. In A), E8 of the RAD9A gene shows a tandem donor with extension/G C A G/; in B) E9 of the ACAD9 gene shows a tandem donor with extension/GTAG/; in C), E15 of the SFRS16 gene shows a tandem donor with extension/GT C A/. Tandem donors in A) and C) were preferentially included in different transcripts. The conservation plot (PHASTCON scores, not in scale with the stated exon and intron nucleotides) covers A5EΔ4 splicing exons, as well as adjacent introns and downstream exons, and shows alternating patterns of high/low levels across all three examples.