title: Identification of three somatostatin genes in lampreys.
abstract: Somatostatins (SSs) are a structurally diverse family of neuropeptides that play important roles in the regulation of growth, development and metabolism in vertebrates. It has been recently proposed that the common ancestor of gnathostomes possessed three SS genes, namely SS1, SS2 and SS5. SS1 and SS2 are still present in most extant gnathostome species investigated so far while SS5 primarily occurs in chondrichthyes, actinopterygians and actinistia but not in tetrapods. Very little is known about the repertoire of SSs in cyclostomes, which are extant jawless vertebrates. In the present study, we report the cloning of the cDNAs encoding three distinct lamprey SS variants that we call SSa, SSb and SSc. SSa and SSb correspond to the two SS variants previously characterized in lamprey, while SSc appears to be a totally novel one. SSa exhibits the same sequence as gnathostome SS1. SSb differs from SSa by only one substitution (Thr12→Ser). SSc exhibits a totally unique structure (ANCRMFYWKTMAAC) that shares only 50% identity with SSa and SSb. SSa, SSb and SSc precursors do not exhibit any appreciable sequence similarity outside the C-terminal region containing the SS sequence. Phylogenetic analyses failed to clearly assign orthology relationships between lamprey and gnathostome SS genes. Synteny analysis suggests that the SSc gene arose before the split of the three gnathostome genes SS1, SS2 and SS5.
authors.affiliation: Evolution des Régulations Endocriniennes, UMR 7221 CNRS, Muséum National d'Histoire Naturelle, Sorbonne Université, Paris, France. Electronic address: htostivi@mnhn.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Tostivint
authors.affiliation: Institut de systématique et Evolution, UMR 7205 CNRS, UMPC, EPHE, Muséum National d'Histoire Naturelle, Sorbonne Université, Paris, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Dettaï
authors.affiliation: Evolution des Régulations Endocriniennes, UMR 7221 CNRS, Muséum National d'Histoire Naturelle, Sorbonne Université, Paris, France.
authors.forename: Feng B
authors.initials: FB
authors.lastname: Quan
authors.affiliation: Institute of Molecular and Cell Biology, A(∗)STAR, Biopolis, Singapore.
authors.forename: Vydianathan
authors.initials: V
authors.lastname: Ravi
authors.affiliation: Institute of Molecular and Cell Biology, A(∗)STAR, Biopolis, Singapore.
authors.forename: Boon-Hui
authors.initials: BH
authors.lastname: Tay
authors.affiliation: Department of Cell Biology and Ecology, CIBUS, Faculty of Biology, University of Santiago de Compostela, Spain.
authors.forename: Maria Celina
authors.initials: MC
authors.lastname: Rodicio
authors.affiliation: Biologie Intégrative des Organismes Marins, UMR 7232 CNRS, Observatoire Océanologique, Université Pierre et Marie Curie, Sorbonne Université, Banyuls-sur-Mer, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Mazan
authors.affiliation: Institute of Molecular and Cell Biology, A(∗)STAR, Biopolis, Singapore.
authors.forename: Byrappa
authors.initials: B
authors.lastname: Venkatesh
authors.affiliation: Evolution des Régulations Endocriniennes, UMR 7221 CNRS, Muséum National d'Histoire Naturelle, Sorbonne Université, Paris, France; Laboratory of Molecular Mechanisms of Neuronal Interactions, Sechenov Insitute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
authors.forename: Natalia B
authors.initials: NB
authors.lastname: Kenigfest
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D007798:Lampreys / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013004:Somatostatin / Q000737:chemistry / Q000235:genetics*; D026801:Synteny / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D013004:Somatostatin
keywords: Agnathans; Cyclostomes; Evolution; Lampreys; Neuropeptides; Somatostatin; Vertebrates; Whole-genome duplication