ZFIN ID: ZDB-PUB-051005-4
Targeted effects of retinoic acid signaling upon photoreceptor development in zebrafish
Prabhudesai, S.N., Cameron, D.A., and Stenkamp, D.L.
Date: 2005
Source: Developmental Biology   287(1): 157-167 (Journal)
Registered Authors: Cameron, David A., Prabhudesai, Shubhangi N., Stenkamp, Deborah L.
Keywords: Photoreceptor, Opsin, Cell fate, Retinoic acid, Danio rerio, Retina, Cone, Nuclear receptor signaling, Differentiation
MeSH Terms:
  • Aldehyde Oxidoreductases/biosynthesis
  • Aldehyde Oxidoreductases/genetics
  • Animals
  • Animals, Genetically Modified
  • Cell Differentiation/physiology*
  • Gene Expression/physiology
  • Genes, Reporter
  • Photoreceptor Cells, Vertebrate/cytology
  • Photoreceptor Cells, Vertebrate/metabolism*
  • Retinal Cone Photoreceptor Cells/cytology
  • Retinal Cone Photoreceptor Cells/metabolism
  • Retinal Rod Photoreceptor Cells/cytology
  • Retinal Rod Photoreceptor Cells/metabolism
  • Rod Opsins/biosynthesis
  • Rod Opsins/genetics
  • Signal Transduction/physiology*
  • Tretinoin/physiology*
  • Zebrafish/embryology*
  • Zebrafish/metabolism
PubMed: 16197938 Full text @ Dev. Biol.
Retinoic acid (RA) is a signaling molecule important for photoreceptor development in vertebrates. The purpose of this study was to examine the mechanisms of the effects of RA upon developing rod and cone photoreceptors in the embryonic zebrafish. Exposure to exogenous RA increased the number of photoreceptors expressing rod opsin and red cone opsin, and decreased the number of photoreceptors expressing the blue and UV cone opsins, suggesting targeted effects of RA on photoreceptor development. RA exposure also increased opsin expression in individual rods and red cones, but decreased opsin expression in individual blue and UV cones, as indicated by differences in the strength of opsin hybridization in identified photoreceptors. RA exposure did not, however, significantly alter quantitative measures of photoreceptor pattern in a manner expected for changes in photoreceptor fate. These observations collectively indicate that RA treatment does not affect photoreceptor fate, but rather differentially influences opsin transcription in determined photoreceptors. An enzyme involved in RA synthesis, RALDH2, was immunocytochemically localized to retinal progenitor cells and the retinal pigmented epithelium (RPE), suggesting the presence of RA in the vicinity of developing photoreceptors. However, expression of an RA response element-driven transgene was restricted to the RPE, retinal progenitors, and a small population of neurons in ventral retina, suggesting that the endogenous RA signaling system is spatially limited within the eye.