ZFIN ID: ZDB-PUB-060731-12
Regulation of hypocretin (OREXIN) expression in embryonic zebrafish
Faraco, J.H., Appelbaum, L., Marin, W., Gaus, S.E., Mourrain, P., and Mignot, E.
Date: 2006
Source: The Journal of biological chemistry   281(40): 29753-29761 (Journal)
Registered Authors: Mourrain, Philippe
Keywords: none
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Gene Expression Regulation, Developmental/physiology*
  • Humans
  • Intracellular Signaling Peptides and Proteins/genetics*
  • Molecular Sequence Data
  • Neuropeptides/biosynthesis*
  • Neuropeptides/genetics*
  • Orexins
  • Promoter Regions, Genetic
  • Zebrafish/embryology*
  • Zebrafish/genetics*
PubMed: 16867991 Full text @ J. Biol. Chem.
Hypocretins/orexins (HCRT) are neuropeptides involved in the regulation of sleep and energy balance in mammals. Conservation of gene sequence, hypothalamic localization of cell bodies, and projection patterns in adult zebrafish suggest that the architecture and function of the hypocretin system are conserved in fish. We report on the complete genomic structure of the zebrafish and Tetraodon hypocretin genes and the complete predicted hypocretin protein sequences from 5 teleosts. Using whole-mount in situ hybridization, we have traced the development of hypocretin cells in zebrafish from onset of expression at 22hpf through the first week of development. Promoter elements of similar size from zebrafish and Tetraodon were capable of driving efficient and specific expression of EGFP in developing zebrafish embryos, thus defining a minimal promoter region able to accurately mimic the native hypocretin pattern. This EGFP expression also revealed a complex pattern of projections within the hypothalamus, to the midbrain, and to the spinal cord. To further analyze the promoter, a series of deletion and substitution constructs were injected into embryos, and resulting promoter activity was monitored in the first week of development. A critical region of 250 base pairs was identified containing a core 13 base pair element essential for hypocretin expression.