Zebrafish Wtx is a negative regulator of Wnt signaling but is dispensable for embryonic development and organ homeostasis

Dev Dyn. 2019 Sep;248(9):866-881. doi: 10.1002/dvdy.84. Epub 2019 Jul 27.

Abstract

Background: The X-chromosomally linked gene WTX is a human disease gene and a member of the AMER family. Mutations in WTX are found in Wilms tumor, a form of pediatric kidney cancer and in patients suffering from OSCS (Osteopathia striata with cranial sclerosis), a sclerosing bone disorder. Functional data suggest WTX to be an inhibitor of the Wnt/β-catenin signaling pathway. Deletion of Wtx in mouse leads to perinatal death, impeding the analysis of its physiological role.

Results: To gain insights into the function of Wtx in development and homeostasis we have used zebrafish as a model and performed both knockdown and knockout studies using morpholinos and transcription activator-like effector nucleases (TALENs), respectively. Wtx knockdown led to increased Wnt activity and embryonic dorsalization. Also, wtx mutants showed a transient upregulation of Wnt target genes in the context of caudal fin regeneration. Surprisingly, however, wtx as well as wtx/amer2/amer3 triple mutants developed normally, were fertile and did not show any anomalies in organ maintenance.

Conclusions: Our data show that members of the zebrafish wtx/amer gene family, while sharing a partially overlapping expression pattern do not compensate for each other. This observation demonstrates a remarkable robustness during development and regeneration in zebrafish.

Keywords: Amer; TALENs; Wilms tumor gene; antisense morpholino.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / physiology*
  • Animals
  • Embryo, Nonmammalian
  • Embryonic Development*
  • Homeostasis*
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Mutant Proteins / pharmacology
  • Nuclear Proteins / genetics
  • Nuclear Proteins / physiology*
  • Regeneration
  • Wnt Signaling Pathway / drug effects*
  • Zebrafish
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / physiology*

Substances

  • Adaptor Proteins, Signal Transducing
  • Membrane Proteins
  • Mutant Proteins
  • Nuclear Proteins
  • Zebrafish Proteins
  • amer1 protein, zebrafish