Figure 3. Likely crossing-over events yielding human PECAM-1 alleles.
The 16 exons of PECAM-1 are widely dispersed amongst introns, with more than 26 kb between the R643G polymorphism in exon 12 and the a2479g nucleotide polymorphism within exon 16. A crossing-over event is likely to have taken place within this region, resulting in the generation of the four major alleles of PECAM-1. Dotted lines illustrate what was likely a second, more recent crossing-over event that has yielded two additional less common PECAM-1 allelic isoforms, previously observed by (Cavanagh et al 2005; Maruya et al 1998). Exon/Intron spacing is drawn to scale.