The alignment of exons with specific domains of merlin reveals the presence of homologous introns. Boxes represent the coding exons with numbers indicated accordingly. The locations of the three commonly discussed domains are marked with horizontal arrows under exons. The boundaries among these domains were defined according to the human merlin protein. The asterisk indicates that the exon structure shown is common to the merlin genes of all vertebrate species studied, including Homo sapiens, Pan troglodytes, Canis familaris, Mus musculus, Rattus norvegicus, Danio rerio, Fugu rubripes, and Xenopus laevis. The overall merlin gene structure of Gallus gallus is similar, except that exons 15 and 16 are fused together in this species.