ZFIN ID: ZDB-PUB-080512-7
Probing Pineal-specific Gene Expression with Transgenic Zebrafish
Kojima, D., Dowling, J.E., and Fukada, Y.
Date: 2008
Source: Photochemistry and photobiology   84(4): 1011-1015 (Journal)
Registered Authors: Dowling, John E., Fukada, Yoshitaka, Kojima, Daisuke
Keywords: none
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Gene Expression Regulation*
  • Green Fluorescent Proteins/genetics
  • Green Fluorescent Proteins/physiology
  • Light
  • Photoreceptor Cells/physiology
  • Photoreceptor Cells/radiation effects
  • Pineal Gland/physiology*
  • Zebrafish/genetics*
PubMed: 18466202 Full text @ Photochem. Photobiol.
The pineal gland of zebrafish (Danio rerio) contains light-sensitive photoreceptor cells and plays an important role in the neuroendocrine system. The zebrafish exorhodopsin gene encodes a pineal-specific photoreceptive protein, whose promoter region harbors a cis-acting element, pineal expression-promoting element (PIPE), directing pineal-specific gene expression. For in vivo genetic studies on PIPE-binding proteins and their regulatory mechanisms, we generated a transgenic zebrafish line, Tg(P(20)-rh/P:gfp), that expresses green fluorescent protein (GFP) under the control of the zebrafish rhodopsin promoter fused with 20 PIPE repeats. In Tg(P(20)-rh/P:gfp) fish, PIPE-dependent gene expression is visualized by GFP fluorescence in the pineal gland along with PIPE-independent GFP signals in the retinal rod photoreceptors. The transgenic fish exhibit detectable and reproducible GFP fluorescence in the larval pineal gland by 5 days postfertilization. Antisense morpholino-mediated knock-down of a pineal transcription factor gene, otx5, suppresses pineal GFP expression in the transgenic line. In a pilot screen of N-ethyl-N-nitrosourea-treated fish of the GFP transgenic line, we isolated potential dominant mutations that cause attenuation of pineal GFP fluorescence with a marginal effect on the retinal GFP signal. The results suggest that the Tg(P(20)-rh/P:gfp) line will be useful for detecting deficits in PIPE-dependent gene expression in the pineal gland.