Regulatory Peptides 95 (2000) 25–34 www.elsevier.com / locate / regpep Molecular evolution of the neuropeptide Y (NPY) family of peptides: cloning of three NPY-related peptides from the sea bass ( Dicentrarchus labrax) a a a, a b * ´ ´ ´ J.M. Cerda-Reverter , G. Martınez-Rodrıguez , S. Zanuy , M. Carrillo , D. Larhammar a ´ Department of Fish Reproduction, Institute of Aquaculture from Torre de la Sal, CSIC, Ribera de Cabanes, 12595 Torre de la Sal, Castellon, Spain b Department of Neuroscience, Unit of Pharmacology, Uppsala University, Box 593, SE-751 24 Uppsala, Sweden Received 1 March 2000; received in revised form 25 May 2000; accepted 25 May 2000 Abstract Neuropeptide Y (NPY) is a 36-amino-acid peptide that is widely and abundantly expressed in the central nervous system of all vertebrates investigated. Related peptides have been found in various vertebrate groups: peptide YY (PYY) is present in gut endocrine cells of many species and pancreatic polypeptide (PP) is made in the pancreas of all tetrapods. In addition, a fish pancreatic peptide called PY has been reported in three species of fishes. The evolutionary relationships of fish PY have been unclear and it has been proposed to be the orthologue (species homologue) of each of the three tetrapod peptides.We demonstrate here with molecular cloning techniques that the sea bass ( Dicentrarchus labrax), an acanthomorph fish, has orthologues of both NPY and PYY as well as a separate PY peptide. Sequence comparisons suggest that PY arose as a copy of the PYY gene, presumably in a duplication event separate from the one that generated PP from PYY in tetrapods. PY sequences from four species of fish indicate that, similar to PP, PY evolves much more rapidly than NPY and PYY. The physiological role of PY is unknown, but we demonstrate here that sea bass PY, like NPY and PYY but in contrast to the tetrapod PP, is expressed in brain.  2000 Elsevier Science B.V. All rights reserved. Keywords: Peptide YY (PYY); Fish pancreatic peptide Y (PY); Pancreatic polypeptide (PP); Gene expression; Gene duplication; Evolution; Fish 1. Introduction hormone or mature peptide requires endoproteolytic pro- cessing at cleavage sites which flank the hormone se- Neuropeptide Y (NPY) belongs to a family of 36-amino- quence [1,3,5,39]. The overall organization of the known acid peptides that also includes peptide YY (PYY), tetra- cDNA sequences encoding different NPY-family peptides pod pancreatic polypeptide (PP), and the fish pancreatic is strikingly similar. Each cDNA includes a 59- and a peptide Y (PY) [1–3]. All four peptides possess the 39-untranslated region and a sequence coding for the necessary residues to adopt the so-called PP-fold, a peptide precursor which consist of a hydrophobic signal hairpin-like structure characterized by a type II proline peptide, the mature peptide, the amidation-proteolytic site helix (residues 1–8) with three prolines and an alpha helix and the carboxyterminal extension [3]. (residues 15–32) with two tyrosines interdigitating with NPY was originally discovered in porcine brain [6] and the three prolines [4]. Like other low molecular-weight subsequently isolated from neural tissue in both tetrapod secreted peptides, the NPY-related peptides are synthesized and non-tetrapod species [3]. It is one of the most highly as larger peptide precursors. The release of the active conserved neuroendocrine peptides [3,7] and is present in the central nervous system (CNS) and the peripheral nervous system (PNS) showing both pre- and post-synaptic *Corresponding author. Tel.: 134-964-319-500; fax: 134-964-319- actions [8,9]. This neuropeptide has been shown to in- 509. E-mail address: zanuy@iats.csic.es (S. Zanuy). fluence a diverse range of physiological functions includ- 0167-0115 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0167-0115(00)00132-4