Fig. 3

PSG genes exist only in primates with hemochorial placentation. Genomic databases of 57 primate species and, for comparison, of four closely related non-primate species (flying lemur, three treeshrew species) were screened for CEACAM genes based on the presence of IgV-like domain (N) exons as described in the Methods section (for genomic data source see Supplementary Table 1). Genes for which no N exons could be identified are shown as white boxes. Genes were registered as pseudogenes when the N domain exons contained stop codon(s) or noncanonical splice acceptor or donor sequences. They are shown in in lighter color. Genes which could not be clearly assigned to orthologous CEACAM1-like genes are shown in purple. If more than one CEACAM3-related gene was found the number of paralogs is shown in the corresponding boxes. The number of GPI-linked CEACAM paralogs in the flying lemur is also indicated. The Latin names from which the species’ acronyms were derived are listed in Supplementary Table 1. The species’ placenta type is indicated at the right