The Wilms tumor gene wtx: connecting the Wnt pathway to pronephros development in zebrafish
Zusammenfassung der Projektergebnisse
Mutations in the Wilms tumor suppressor gene WTX cause a pediatric kidney tumor as well as a disease of the bone. In this project we used zebrafish as a model to gain insights into the molecular function of wtx. We focused on two different approaches. First we examined the impact of wtx on patterning of the early zebrafish embryo. Using morpholino-based inactivation of wtx we observed a so-called dorsalization of the early embryo. The latter describes an expansion of dorsal domains with simultaneous reduction of ventral domains, a phenomenon, which is often caused by activation of the Wnt/β-catenin signaling pathway. Thus, our data suggest that Wtx acts as a negative regulator of Wnt/β-catenin signaling. Upon knockdown of wtx, the Wnt pathway gets up-regulated resulting in patterning defects in the early embryo. In a second approach we generated mutant zebrafish lines for wtx as well as its family members amer2 and amer3. A single and combinatorial action of transcription activator-like effector nucleases (TALENs) was successfully used to disrupted wtx by either small indel mutations or large intragenic deletions. In contrast to mammals, homozygous wtx mutants were viable and fertile. The results suggest that Wtx is dispensable for embryonic development in zebrafish. Of note, the lack of an embryonic phenotype was not due to compensation by wtx gene family members amer2 and amer3, as triple homozygous mutant embryos did not enhance an embryonic phenotype. Results obtained from caudal fin regeneration experiments revealed that mutations in wtx are associated with molecular alterations in this process. By showing enhanced Wnt/ β-catenin activity in wtx mutants, the data confirmed Wtx to have a conserved function as a negative regulator of Wnt/β-catenin signaling, similar to that of mammals.
Projektbezogene Publikationen (Auswahl)
- (2016) Genomic engineering of Wilms tumour genes in Danio rerio
Andreas Große
- The impact of the Wilms tumor suppressor genes on zebrafish kidney regeneration. Dissertation, Friedrich-Schiller-Universität Jena, 2018. 88, XVII Blätter
Uta Naumann
