Example of a PAP. (A) Graphical representation of a PAP involving the two pairs of paralogous genes ABLIM2/ABLIM3 and SH2TC3/SH2TC2. Chromosome schemes were taken from the Ensembl genome browser (Hubbard et al., 2009). Gene pairs displayed in each chromosome are not homologous and the duplicated pairs have conserved the adjacency and the relative strand position. (B) Phylogenetic trees of the genes involved in the segmental duplication. Duplication events creating the pairs ABLIM2/ABLIM3 and SH2TC3/SH2TC2 are marked in the trees with red and green colors, respectively. Note that relative dating based on phylogenetic trees detects, in both cases, a duplication preceding the radiation of vertebrates, suggesting that they got duplicated at the same relative time.