ZFIN ID: ZDB-PUB-181115-8
γ-Tubulin small complex formation is essential for early zebrafish embryogenesis
Pouchucq, L., Undurraga, C.A., Fuentes, R., Cornejo, M., Allende, M.L., Monasterio, O.
Date: 2018
Source: Mechanisms of Development   154: 145-152 (Journal)
Registered Authors: Allende, Miguel L., Undurraga, Cristian
Keywords: Cytoskeleton, Microtubules nucleation, Morpholino, qPCR, γ-TuRC, γ-TuSC
MeSH Terms:
  • Animals
  • Apoptosis/physiology
  • Cell Cycle/physiology
  • Cell Nucleus/metabolism
  • Cell Proliferation/physiology
  • Cytoplasm/metabolism
  • Embryonic Development/physiology*
  • Microtubule-Associated Proteins/metabolism
  • Spindle Apparatus/metabolism
  • Tubulin/metabolism*
  • Zebrafish/embryology*
  • Zebrafish/metabolism*
PubMed: 30426927 Full text @ Mech. Dev.
The centrosomal protein γ-tubulin is part of the cytoplasmic γ-tubulin small (γ-TuSCs) and large complexes (γ-TuRCs). Both, molecular and cellular evidence indicate that γ-tubulin plays a central role in microtubule nucleation and mitotic spindle formation. However, the molecular mechanisms of complex formation and subsequent biological roles in animal development remain unclear. Here, we used γ-tubulin gene knockdown in the zebrafish early embryo model to gain insights into its activity and cellular contribution during vertebrate embryogenesis. γ-Tubulin loss-of-function impaired γ-TuSC formation, impacting the microtubule nucleation rate in vitro. Moreover, decreased γ-tubulin synthesis caused dramatic defects in nuclear dynamics and cell cycle progression, leading to developmental arrest at the mid-gastrula stage. At the subcellular level, microtubule organization and function were altered, affecting chromosome segregation and triggering cell proliferation arrest and apoptosis. Our results suggest that de novo translated γ-tubulin participates in γ-TuSC formation required for early animal development. Importantly, formation of this complex is essential for both centrosome assembly and function, and cell proliferation. Thus, γ-TuSC integrity appears to be critical for cell cycle progression, and concomitantly, for coordinating the many distinct activities carried out by the early embryo. Our findings identify a novel role for γ-TuSC in the regulation of early vertebrate embryogenesis, providing molecular and biochemical starting points for future in depth studies of γ-tubulin functionality and its specific role in development.