Figure 8
Delineation of regions with gene conversion/recombination events between putative paired carcinoembryonic antigen related cell adhesion molecule (CEACAM) receptor genes. Nucleotide sequences of immunoreceptor tyrosine-based inhibition motif (ITIM)/immunoreceptor tyrosine-based switch motif (ITSM)-encoding CEACAM genes from humans (A), cattle (B), opossum (C, D) and dogs (E) were compared with the sequences of CEACAM genes coding for their most closely related, putative paired receptor (gene names are shown in the lower right corner of the plot). For contiguous stretches of nucleotides conserved between gene pairs, the degree of identity was calculated and displayed as horizontal lines. The location of exons is indicated by numbered boxes. Genomic regions involved in gene conversion/recombination are marked with red boxes, involved N exons are shown in red. Note that these regions exhibit the highest degree of conservation. Repeat sequences indicated by differently shaped forms (see box for detailed explanation) have preferentially accumulated in most ITIM/ITSM-encoding genes between the immunoglobulin constant-like domain and the transmembrane domain exons. N, N domain exon; TM, transmembrane domain exon.