Fig. 2. Homology between Nkx6 proteins. (A) Alignment of fly and zebrafish Nkx6 translated amino acid sequence reveals several regions of high identity: the almost invariant NK domain (dashed line) and homeodomain (solid line), and two other regions indicated by asterisks. Fly Nkx6 was trimmed of the N-terminus. (B) Maximum likelihood tree. Fly Nkx6 is orthologous to vertebrate Nkx6 proteins, distinct from Vnd/Nkx2.2 proteins. Numbers at the nodes represent bootstrap values. Dm, Drosophila melanogaster; Dr, Danio rerio.