Tri-phasic expression of posterior Hox genes during development of pectoral fins in zebrafish: Implications for the evolution of vertebrate paired appendages

Ahn, D., and Ho, R.K.
Developmental Biology   322(1): 220-233 (Journal)
Registered Authors
Ahn, Dae-gwon, Ho, Robert K.
Hox, fin, limb, evolution, development, zebrafish, Shh, digit enhancer
MeSH Terms
  • Animals
  • Biological Evolution*
  • Body Patterning/genetics*
  • Cloning, Molecular
  • Embryo, Nonmammalian
  • Enhancer Elements, Genetic
  • Extremities/embryology*
  • Gene Expression Regulation, Developmental*/drug effects
  • Hedgehog Proteins/genetics
  • Hedgehog Proteins/physiology
  • Homeodomain Proteins/biosynthesis
  • Homeodomain Proteins/genetics*
  • Immunohistochemistry
  • In Situ Hybridization
  • Molecular Sequence Data
  • Morphogenesis/genetics
  • Teratogens/pharmacology
  • Time Factors
  • Veratrum Alkaloids/pharmacology
  • Vertebrates/embryology
  • Zebrafish/embryology
  • Zebrafish/genetics*
  • Zebrafish Proteins/biosynthesis
  • Zebrafish Proteins/genetics
18638469 Full text @ Dev. Biol.
During development of the limbs, Hox genes belonging to the paralogous groups 9-13 are expressed in three distinct phases, which play key roles in the segmental patterning of limb skeletons. In teleost fishes, which have a very different organization in their fin skeletons, it is not clear whether a similar patterning mechanism is at work. To determine whether Hox genes are also expressed in several distinct phases during teleost paired fin development, we re-analyzed the expression patterns of hox9-13 genes during development of pectoral fins in zebrafish. We found that, similar to tetrapod Hox genes, expression of hoxa/d genes in zebrafish pectoral fins occurs in three distinct phases, in which the most distal/third phase is correlated with the development of the most distal structure of the fin, the fin blade. Like in tetrapods, hox gene expression in zebrafish pectoral fins during the distal/third phase is dependent upon sonic hedgehog signaling (hoxa and hoxd genes) and the presence of a long-range enhancer (hoxa genes), which indicates that the regulatory mechanisms underlying tri-phasic expression of Hox genes have remained relatively unchanged during evolution. Our results suggest that, although simpler in organization, teleost fins do have a distal structure that might be considered comparable to the autopod region of limbs.
Genes / Markers
Figure Gallery
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Engineered Foreign Genes
Errata and Notes