Hansen, Carsten

Feng, Yi

Riley, Susanna Elizabeth

Medical Research Council (MRC)

2024-03-06T14:51:40Z

2024-03-06T14:51:40Z

2024-03-06

The Hippo pathway is a kinase signalling cascade involved in the regulation of organ size, tissue homeostasis, and stem cell proliferation. Dysfunction of this pathway is associated with carcinogenesis, fibrosis, and defects in development and regeneration. The key effectors of the Hippo pathway are YAP and TAZ, which translocate to the nucleus, bind to transcription factors, and induce transcription when Hippo signalling is off. The wide-ranging role of the Hippo pathway means that it must be strictly regulated, and so context-dependent molecular understanding is needed for it to be manipulated therapeutically. However, the function of individual components of the pathway is not well understood, and a direct comparison of the different roles of Hippo pathway components has so far mainly been carried out in vitro. To study these functions in vivo, a range of zebrafish Hippo pathway CRISPR mutants (CRISPants) were generated and analysed as part of a medium-throughput screen to identify regenerative and developmental phenotypes. Many developmental phenotypes were identified and quantified that match those reported in previous publications, as well as multiple novel findings. Neuromast and tail fin regeneration phenotypes were also identified. Notable phenotypes include differences between yap1 and wwtr1 CRISPants, and a selective reduction in severe tail fin regeneration in wwtr1 CRISPants but no consistent phenotype in any other developmental or regenerative parameter. Preliminary analysis of molecular and cellular drivers of this tail fin regeneration was performed, including the analysis of RNAseq data, immunofluorescence labelling of both proteins and mRNA, and live imaging of multiple transgenic lines after tail fin injury. These enabled a separation of yap1 and wwtr1 CRISPant phenotypes at a molecular and cellular level. The generation and characterisation of a ctgfa:GFP reporter transgenic line and Yap1 and Taz stable mutant lines are also reported. Overall, the project provides insights into Hippo component-specific regulation of development and regeneration in both teleosts and mammals.

https://hdl.handle.net/1842/41599

http://dx.doi.org/10.7488/era/4331

en

The University of Edinburgh

Riley, S. E., Feng, Y. & Gram Hansen, C. Hippo-Yap/Taz signalling in zebrafish regeneration. NPJ Regen Med 7, (2022)

CRISPR

zebrafish

Hippo pathway

In vivo investigation of component-specific functions of the Hippo pathway

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy