Murashita K, Kurokawa T, Nilsen TO, Rønnestad I. Ghrelin, cholecystokinin, and peptide YY in Atlantic salmon (Salmo salar): molecular cloning and tissue expression.
Gen Comp Endocrinol 2009;
160:223-35. [PMID:
19073185 DOI:
10.1016/j.ygcen.2008.11.024]
[Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 11/18/2008] [Accepted: 11/19/2008] [Indexed: 10/21/2022]
Abstract
Gastrointestinal (GI) peptide hormones, ghrelin (GHRL), cholecystokinin (CCK), and peptide YY (PYY) genes were identified in Atlantic salmon, Salmo salar. Full-length cDNAs encoding two isoforms of GHRL (GHRL-1 and GHRL-2), two isoforms of CCK (CCK-L and CCK-N) and peptide YY (PYY) cDNA were obtained. The GHRL-1 and GHRL-2 genes encoded proteins of 111- and 108-amino acids, respectively. Both types of GHRL were mainly expressed in the stomach, but also weakly expressed in the pyloric caeca, mid-gut, adipose tissue, and testis. The CCK-L and CCK-N genes encoded preproproteins of 132- and 140-amino acids, respectively. Both types of CCK were strongly expressed in the brain and comparatively weakly expressed in other tissues, including the digestive tract. In the digestive tract, CCK-L was mainly expressed in the pyloric caeca and hind-gut, while CCK-N was only expressed in the pyloric caeca. The PYY gene encoded for 97-amino acid residues and was mainly expressed in the brain and anterior part of the intestine, including the pyloric caeca. In an experiment, we demonstrated that 6 days starvation led to, increased GHRL-1 mRNA levels in the GI tract (stomach), while there no significant changes in expression levels for the other hormones in the GI tract. This suggests an orexigenic role for GHRL-1 in Atlantic salmon. These data contribute to elucidate the functional relationships among teleost gastrointestinal peptide hormones.
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