The Hippo pathway effector Taz is required for cell morphogenesis and fertilization in zebrafish

Development. 2018 Nov 22;145(22):dev167023. doi: 10.1242/dev.167023.

Abstract

Hippo signaling is a critical pathway that integrates extrinsic and intrinsic mechanical cues to regulate organ size. Despite its essential role in organogenesis, little is known about its role in cell fate specification and differentiation. Here, we unravel a novel and unexpected role of the Hippo pathway effector Taz (wwtr1) in controlling the size, shape and fate of a unique cell in the zebrafish ovary. We show that wwtr1 mutant females are infertile. In teleosts, fertilization occurs through the micropyle, a funnel-like opening in the chorion, formed by a unique enlarged follicle cell, the micropylar cell (MC). We describe here, for the first time, the mechanism that underlies the differentiation of the MC. Our genetic analyses show that Taz is essential for MC fate acquisition and subsequent micropyle formation in zebrafish. We identify Taz as the first bona fide MC marker and show that Taz is specifically and strongly enriched in the MC precursor. Altogether, we performed the first genetic and molecular characterization of the MC and propose that Taz is a key regulator of MC fate.This article has an associated 'The people behind the papers' interview.

Keywords: Fertilization; Hippo; Micropylar cell; Micropyle; Taz; Zebrafish.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / drug effects
  • Adherens Junctions / metabolism
  • Animals
  • Biomarkers / metabolism
  • Cell Polarity / drug effects
  • Cell Shape / drug effects
  • Cytochalasin D / pharmacology
  • Female
  • Fertilization* / drug effects
  • Infertility, Female / genetics
  • Infertility, Female / pathology
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Microtubules / drug effects
  • Microtubules / metabolism
  • Models, Biological
  • Morphogenesis* / drug effects
  • Mutation / genetics
  • Oocytes / drug effects
  • Oocytes / metabolism
  • Oocytes / pathology
  • Ovum / drug effects
  • Ovum / metabolism
  • Protein Serine-Threonine Kinases / metabolism*
  • Serine-Threonine Kinase 3
  • Signal Transduction*
  • Tight Junctions / drug effects
  • Tight Junctions / metabolism
  • Transcriptional Coactivator with PDZ-Binding Motif Proteins
  • Zebrafish / growth & development*
  • Zebrafish / metabolism*
  • Zebrafish Proteins / metabolism*

Substances

  • Biomarkers
  • Intracellular Signaling Peptides and Proteins
  • Transcriptional Coactivator with PDZ-Binding Motif Proteins
  • WWTR1 protein, zebrafish
  • Zebrafish Proteins
  • Cytochalasin D
  • Protein Serine-Threonine Kinases
  • Serine-Threonine Kinase 3
  • stk3 protein, zebrafish