Regulation of segmental patterning by retinoic acid signaling during Xenopus somitogenesis

Dev Cell. 2004 Feb;6(2):205-18. doi: 10.1016/s1534-5807(04)00026-7.

Abstract

Somites, the segmented building blocks of the vertebrate embryo, arise one by one in a patterning process that passes wavelike along the anteroposterior axis of the presomitic mesoderm (PSM). We have studied this process in Xenopus embryos by analyzing the expression of the bHLH gene, Thylacine1, which is turned on in the PSM as cells mature and segment, in a pattern that marks both segment boundaries and polarity. Here, we show that this segmental gene expression involves a PSM enhancer that is regulated by retinoic acid (RA) signaling at two levels. RA activates Thylacine1 expression in rostral PSM directly. RA also activates Thylacine1 expression in the caudal PSM indirectly by inducing the expression of MKP3, an inhibitor of the FGF signaling pathway. RA signaling is therefore a major contributor to segmental patterning by promoting anterior segmental polarity and by interacting with the FGF signaling pathway to position segmental boundaries.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Antibodies / metabolism
  • Body Patterning / genetics
  • Body Patterning / physiology*
  • Cells, Cultured
  • Cycloheximide / pharmacology
  • Drug Interactions
  • Embryo, Nonmammalian
  • Gene Expression Regulation, Developmental / drug effects
  • Gene Expression Regulation, Developmental / physiology*
  • Immunohistochemistry
  • Membrane Proteins / metabolism
  • Models, Biological
  • Muscles / immunology
  • Muscles / metabolism
  • Naphthalenes / pharmacology
  • Protein Synthesis Inhibitors / pharmacology
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Pyrroles / pharmacology
  • Receptors, Notch
  • Receptors, Retinoic Acid / antagonists & inhibitors
  • Receptors, Retinoic Acid / genetics
  • Receptors, Retinoic Acid / metabolism
  • Retinoic Acid Receptor alpha
  • Signal Transduction / physiology*
  • Somites / cytology
  • Somites / metabolism*
  • Thy-1 Antigens / genetics
  • Thy-1 Antigens / metabolism
  • Time Factors
  • Transfection
  • Tretinoin / physiology*
  • Xenopus / embryology*
  • Xenopus Proteins / genetics
  • Xenopus Proteins / metabolism
  • Xenopus laevis

Substances

  • Antibodies
  • Membrane Proteins
  • Naphthalenes
  • Protein Synthesis Inhibitors
  • Pyrroles
  • Receptors, Notch
  • Receptors, Retinoic Acid
  • Retinoic Acid Receptor alpha
  • SU 5402
  • Thy-1 Antigens
  • Xenopus Proteins
  • Tretinoin
  • Cycloheximide
  • Protein-Tyrosine Kinases
  • AGN 193109