Beta-actin is required for proper mouse neural crest ontogeny

PLoS One. 2014 Jan 7;9(1):e85608. doi: 10.1371/journal.pone.0085608. eCollection 2014.

Abstract

The mouse genome consists of six functional actin genes of which the expression patterns are temporally and spatially regulated during development and in the adult organism. Deletion of beta-actin in mouse is lethal during embryonic development, although there is compensatory expression of other actin isoforms. This suggests different isoform specific functions and, more in particular, an important function for beta-actin during early mammalian development. We here report a role for beta-actin during neural crest ontogeny. Although beta-actin null neural crest cells show expression of neural crest markers, less cells delaminate and their migration arrests shortly after. These phenotypes were associated with elevated apoptosis levels in neural crest cells, whereas proliferation levels were unchanged. Specifically the pre-migratory neural crest cells displayed higher levels of apoptosis, suggesting increased apoptosis in the neural tube accounts for the decreased amount of migrating neural crest cells seen in the beta-actin null embryos. These cells additionally displayed a lack of membrane bound N-cadherin and dramatic decrease in cadherin-11 expression which was more pronounced in the pre-migratory neural crest population, potentially indicating linkage between the cadherin-11 expression and apoptosis. By inhibiting ROCK ex vivo, the knockout neural crest cells regained migratory capacity and cadherin-11 expression was upregulated. We conclude that the presence of beta-actin is vital for survival, specifically of pre-migratory neural crest cells, their proper emigration from the neural tube and their subsequent migration. Furthermore, the absence of beta-actin affects cadherin-11 and N-cadherin function, which could partly be alleviated by ROCK inhibition, situating the Rho-ROCK signaling in a feedback loop with cadherin-11.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics*
  • Actins / metabolism
  • Animals
  • Apoptosis / genetics
  • Biomarkers
  • Cadherins / genetics
  • Cell Movement / genetics
  • Gene Expression Regulation, Developmental
  • Mice
  • Mice, Knockout
  • Models, Biological
  • Neural Crest / cytology
  • Neural Crest / embryology*
  • Neural Crest / metabolism*
  • Neural Crest / pathology
  • Neurogenesis / genetics
  • Signal Transduction
  • Vimentin / genetics
  • Vimentin / metabolism
  • rho GTP-Binding Proteins / metabolism
  • rho-Associated Kinases / antagonists & inhibitors
  • rho-Associated Kinases / metabolism

Substances

  • Actins
  • Biomarkers
  • Cadherins
  • Vimentin
  • rho-Associated Kinases
  • rho GTP-Binding Proteins

Grants and funding

This work was supported by the Queen Elisabeth Medical Foundation for neuroscience (QEMF, Belgium) and by the Fund for Scientific Research – Flanders (FWO, Belgium). DT is a pre doctoral fellow of this Fund and CA received a research grant G.0441.10N. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.