PUBLICATION

Specific teratogenic effects of different retinoic acid isomers and analogs in the developing anterior central nervous system of zebrafish

Authors
Zhang, Z., Balmer, J.E., Lovlie, A., Fromm, S.H., and Blomhoff, R.
ID
ZDB-PUB-961014-1298
Date
1996
Source
Developmental Dynamics : an official publication of the American Association of Anatomists   206: 73-86 (Journal)
Registered Authors
Keywords
9-cis retinoic acid, All-trans retinoic acid, Anterior CNS, Axonal tract, hlx-1, pax-2, Zebrafish, Embryo
MeSH Terms
  • Animals
  • Axons/drug effects
  • Brain/drug effects
  • Brain/embryology*
  • DNA-Binding Proteins/metabolism
  • Embryonic and Fetal Development
  • Gestational Age
  • Homeodomain Proteins/metabolism
  • Isomerism
  • PAX2 Transcription Factor
  • Retinoids/pharmacology
  • Stereoisomerism
  • Teratogens/pharmacology*
  • Transcription Factors/metabolism
  • Transfection
  • Tretinoin/analogs & derivatives
  • Tretinoin/pharmacology*
  • Zebrafish/embryology*
  • Zebrafish Proteins
PubMed
9019248 Full text @ Dev. Dyn.
Abstract
Vertebrate embryos are sensitive to retinoic acid, either in deficiency or in excess. Although all-trans retinoic acid (RA) and 9-cis RA are known to have distinct but overlapping activities in higher organisms, only the all-trans isomer has been investigated in detail as a teratogen in zebrafish. We have identified profound and specific effects of 9-cis RA when administered to zebrafish embryos, and have confirmed the results of prior studies on the teratogenic effects of exogenous all-trans RA. Moreover, we have identified a 1-hr period during gastrulation in which embryos are particularly sensitive to the teratogenic effects of RA. In the course of these investigations, we have also studied the effects of two synthetic retinoids-a 9-cis RA analog, SR11217, and an all-trans RA analog, TTAB. An application of all-trans RA to the early zebrafish gastrula leads to defects that are limited to the caudal midbrain and rostral hindbrain. Our experiments show that an application of exogenous 9-cis RA for a period as short as 1 hr and at a concentration as low as 0.1 mu M can block differentiation of the rostral CNS. We have observed abnormal phenotypes using DIC optics, and have demonstrated further abnormalities using whole-mount immunocytochemical staining with antibodies to HNK-1 and acetylated alpha-tubulin. Major axon tract formation in the anterior CNS is unambiguously disrupted by the administration of 9-cis RA but not all-trans RA. Furthermore, exogenous 9-cis RA produces a qualitative alteration in the multiple-site expression pattern of the hlx-1 gene within the rostral CNS, while treatment with all-trans RA leads only to a weakened expression signal. The administration of TTAB and SR11217 result in distinctive inhibitions of hlx-1 expression. Unlike all-trans RA, which causes premature par-2 expression in the posterior midbrains of a majority of embryos, 9-cis RA leads to a complete deletion of this domain throughout development. These results suggest that 9-cis RA is a more active teratogen than all-trans RA in rostral CNS structures of the zebrafish embryo.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping