Figure 4
From: Improvement of Dscam homophilic binding affinity throughout Drosophilaevolution
A schematic model depicting the evolution of Dscam1 in arthropods. ND-exons were created by exon duplication and/or sequence mutation. Over time, all isoforms containing old and ND-exons were under selection pressures for higher homophilic binding. Only those exons contributing to higher homophilic binding affinities were retained throughout evolution, and can be found in current genome.