- Title
- Changes in the ghrelin hormone pathway maybe part of an unusual gastric system in monotremes
- Creator
- He, Chuan; Tsend-Ayush, Enkhjargal; Myers, Mark; Forbes, Briony; Grützner, Frank
- Date
- 2013
- Type
- Text; Journal article
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/69334
- Identifier
- vital:5130
- Identifier
-
https://doi.org/10.1016/j.ygcen.2013.06.003
- Identifier
- ISSN:0016-6480
- Abstract
- Ghrelin is a growth hormone (GH)-releasing and appetite-regulating peptide predominately released from the stomach. Ghrelin is evolutionarily highly conserved and known to have a wide range of functions including the regulation of metabolism by maintaining an insulin-glucose balance. The peptide is produced as a single proprotein, which is later proteolytically cleaved. Ghrelin exerts its biological function after O-n-octanoylation at residue serine 3, which is catalyzed by ghrelin O-acyl transferase (GOAT) and allows binding to the growth hormone secretagogue receptor (GHS-R 1a). Genes involved in the ghrelin pathway have been identified in a broad range of vertebrate species, however, little is known about this pathway in the basal mammalian lineage of monotremes (platypus and echidna). Monotremes are particularly interesting in this context, as they have undergone massive changes in stomach anatomy and physiology, accompanied by a striking loss of genes involved in gastric function. In this study, we investigated genes in the ghrelin pathway in monotremes. Using degenerate PCR, database searches and synteny analysis we found that genes encoding ghrelin and GOAT are missing in the platypus genome, whilst, as has been reported in other species, the GHSR is present and expressed in brain, pancreas, kidney, intestine, heart and stomach. This is the first report suggesting the loss of ghrelin in a mammal. The loss of this gene may be related to changes to the platypus digestive system and raises questions about the control of blood glucose levels and insulin response in monotreme mammals. In addition, the conservation of the ghrelin receptor gene in platypus indicates that another ligand(s) maybe acting via this receptor in monotremes. © 2013 Elsevier Inc.
- Relation
- General and Comparative Endocrinology Vol. 191, no. (2013), p. 74-82
- Rights
- Copyright 2013 Elsevier
- Rights
- Open Access
- Rights
- This metadata is freely available under a CCO license
- Subject
- 0606 Physiology; 0608 Zoology; 0707 Veterinary Sciences; Evolution; Ghrelin; GHS-R 1a; GOAT; Metabolic control; Monotremes; Acyltransferase; Ghrelin o acyl transferase; Ghrelin receptor; Obestatin; Echidna; Gene expression; Gene function; Gene identification; Gene loss; Genome analysis; GHSR gene; Nucleotide sequence; Platypus; Stomach anatomy; Stomach function
- Full Text
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