Sample Species of NCX Homologs Exon Splicing Pattern. Three sample organisms for mammalian (Homo sapiens), reptilian (Anolis carolinensis), amphibian (Xenopus tropicalis) and teleost (Danio rerio) are shown aligned at exon A (blue)/B (orange). Light blue rectangles belong to NCX N-terminus before the alternative spliced exons and yellow rectangles represent the C-terminus after the alternative spliced region. Cassette exons (C-F) are indicated in light green, purple, red and dark green where it is applicable and respectively. Distances between exons are scaled as indicated on the legend but not the length of the exons.