The phylogenetic tree of vertebrate NPY. Scale bar indicates the substitution rate per residue. Numbers at nodes indicate the bootstrap value, as percentages, obtained per 1000 replicates. GenBank accession numbers: Typhlonectes natans (AAD48033), Xenopus laevis (NP_001081300), Ambystoma mexicanum (AAT66407), Bos taurus (AAR37328), Homo sapiens (AAA59944), Torpedo marmorata (AAA49281), Oncorhynchus mykiss (AAB25269), Salmo salar (BAH24101), Gadus morhua (AAX19943), Siniperca chuatsi (ABS83815), Dicentrarchus labrax (CAB64932), Paralichthys olivaceus (BAB62409), Ictalurus punctatus (AAF71617), Danio rerio (NP_571149), Carassius auratus (AAA49186), Spinibarbus sinensis (ABE73783).