Exon arrangement of canine CEACAM1-related genes. The exon types are indicated by differently colored boxes. 5'- and 3'-UTR are shown as gray, IgV-like domain exons as red, IgC-like domain exons as blue and transmembrane domain exons as black boxes. The exons encoding the cytoplasmic domain with an ITIM or an ITAM motif are shown in red and blue, respectively. The size of the 3'-UTR is inferred from the position of the first putative polyadenylation signal sequence (AATAAA) after the stop codon. The presence of deletions/insertions in exons causing reading frame shifts or mutational corrupted splice donor and acceptor consensus sequences are indicated by an asterisk. No leader exon could be identified for CEACAM23 because of a sequence gap (indicated by brackets) in the publicly available genomic sequences. The genes are arranged in the order and orientation as found on dog chromosome 1.