ZFIN ID: ZDB-PUB-210204-1
The Axenfeld-Rieger Syndrome Gene FOXC1 Contributes to Left-Right Patterning
Chrystal, P.W., French, C.R., Jean, F., Havrylov, S., van Baarle, S., Peturson, A.M., Xu, P., Crump, J.G., Pilgrim, D.B., Lehmann, O.J., Waskiewicz, A.J.
Date: 2021
Source: Genes   12(2): (Journal)
Registered Authors: French, Curtis R., Lehmann, Ordan J., Pilgrim, David, Waskiewicz, Andrew
Keywords: Axenfeld–Rieger syndrome, FOXC1, LEFTY, left–right patterning, zebrafish
MeSH Terms:
  • Alleles
  • Animals
  • Anterior Eye Segment/abnormalities*
  • Computational Biology/methods
  • Disease Models, Animal
  • Eye Abnormalities/diagnosis*
  • Eye Abnormalities/etiology*
  • Eye Diseases, Hereditary/diagnosis*
  • Eye Diseases, Hereditary/etiology*
  • Forkhead Transcription Factors/genetics*
  • Gene Expression Profiling
  • Genetic Association Studies*/methods
  • Genetic Predisposition to Disease*
  • Genotype
  • Humans
  • Mesoderm/embryology
  • Mesoderm/metabolism
  • Mutation
  • Phenotype*
  • Zebrafish
PubMed: 33530637 Full text @ Genes (Basel)
Precise spatiotemporal expression of the Nodal-Lefty-Pitx2 cascade in the lateral plate mesoderm establishes the left-right axis, which provides vital cues for correct organ formation and function. Mutations of one cascade constituent PITX2 and, separately, the Forkhead transcription factor FOXC1 independently cause a multi-system disorder known as Axenfeld-Rieger syndrome (ARS). Since cardiac involvement is an established ARS phenotype and because disrupted left-right patterning can cause congenital heart defects, we investigated in zebrafish whether foxc1 contributes to organ laterality or situs. We demonstrate that CRISPR/Cas9-generated foxc1a and foxc1b mutants exhibit abnormal cardiac looping and that the prevalence of cardiac situs defects is increased in foxc1a-/-; foxc1b-/- homozygotes. Similarly, double homozygotes exhibit isomerism of the liver and pancreas, which are key features of abnormal gut situs. Placement of the asymmetric visceral organs relative to the midline was also perturbed by mRNA overexpression of foxc1a and foxc1b. In addition, an analysis of the left-right patterning components, identified in the lateral plate mesoderm of foxc1 mutants, reduced or abolished the expression of the NODAL antagonist lefty2. Together, these data reveal a novel contribution from foxc1 to left-right patterning, demonstrating that this role is sensitive to foxc1 gene dosage, and provide a plausible mechanism for the incidence of congenital heart defects in Axenfeld-Rieger syndrome patients.