PUBLICATION
Expression of Glucose-Dependent-Insulinotropic Polypeptide (GIP) in the Zebrafish
- Authors
- Musson, M.C., Jepeal, L.I., Mabray, P.D., Zhdanova, I.V., Cardoso, W.V., and Wolfe, M.M.
- ID
- ZDB-PUB-091005-7
- Date
- 2009
- Source
- American journal of physiology. Regulatory, integrative and comparative physiology 297(6): R1803-R1812 (Journal)
- Registered Authors
- Zhdanova, Irina
- Keywords
- none
- MeSH Terms
-
- Age Factors
- Aging/genetics
- Aging/metabolism
- Amino Acid Sequence
- Animals
- Female
- Food Deprivation
- Gastric Inhibitory Polypeptide/genetics
- Gastric Inhibitory Polypeptide/metabolism*
- Gene Expression Regulation, Developmental
- Immunohistochemistry
- In Situ Hybridization
- Insulin/genetics
- Insulin/metabolism
- Intestines/embryology
- Intestines/metabolism
- Larva/genetics
- Larva/metabolism
- Ligands
- Male
- Molecular Sequence Data
- Pancreas/embryology
- Pancreas/metabolism
- Proglucagon/genetics
- RNA, Messenger/metabolism
- Rats
- Receptors, Gastrointestinal Hormone/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism*
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism*
- PubMed
- 19793957 Full text @ Am. J. Physiol. Regul. Integr. Comp. Physiol.
Citation
Musson, M.C., Jepeal, L.I., Mabray, P.D., Zhdanova, I.V., Cardoso, W.V., and Wolfe, M.M. (2009) Expression of Glucose-Dependent-Insulinotropic Polypeptide (GIP) in the Zebrafish. American journal of physiology. Regulatory, integrative and comparative physiology. 297(6):R1803-R1812.
Abstract
In mammals, glucose-dependent insulinotropic polypeptide (GIP) is synthesized predominately in the small intestine and functions in conjunction with insulin to promote nutrient deposition. However, little is known regarding GIP expression and function in early vertebrates like the zebrafish, a model organism representing an early stage in the evolutionary development of the compound vertebrate pancreas. Analysis of GIP and insulin (insa) expression in zebrafish larvae by RT-PCR demonstrated that although insa was detected as early as 24 hours post-fertilization (hpf), GIP expression was not demonstrated until 72 hpf, shortly after the completion of endocrine pancreatic development but prior to the commencement of independent feeding. Furthermore, whole-mount in situ hybridization of zebrafish larvae showed expression of GIP and insa in the same tissues and in adult zebrafish, RT-PCR and immunohistochemistry demonstrated GIP expression in both the intestine and the pancreas. Receptor activation studies showed that zebrafish GIP was capable of activating the rat GIP receptor (GIPR). Although previous studies have identified four receptors with glucagon receptor-like sequences in the zebrafish, one of which possesses the capacity to bind GIP, a functional analysis of these receptors has not been performed. This study demonstrates interactions between the latter receptor and zfGIP, identifying it as a potential in vivo target for the ligand. Finally, food deprivation studies in larvae demonstrated an increase in GIP and proglucagon II mRNA levels in response to fasting. In conclusion, the results of these studies suggest that although the zebrafish appears to be a model of an early stage of evolutionary development of GIP expression, the peptide may not possess incretin properties in this species. Key words: incretin hormones, enteroinsular axis, endocrine pancreas.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping