Diversity of left-right symmetry breaking strategy in animals

F1000Res. 2020 Feb 19:9:F1000 Faculty Rev-123. doi: 10.12688/f1000research.21670.1. eCollection 2020.

Abstract

Left-right (L-R) asymmetry of visceral organs in animals is established during embryonic development via a stepwise process. While some steps are conserved, different strategies are employed among animals for initiating the breaking of body symmetry. In zebrafish (teleost), Xenopus (amphibian), and mice (mammal), symmetry breaking is elicited by directional fluid flow at the L-R organizer, which is generated by motile cilia and sensed by mechanoresponsive cells. In contrast, birds and reptiles do not rely on the cilia-driven fluid flow. Invertebrates such as Drosophila and snails employ another distinct mechanism, where the symmetry breaking process is underpinned by cellular chirality acquired downstream of the molecular interaction of myosin and actin. Here, we highlight the convergent entry point of actomyosin interaction and planar cell polarity to the diverse L-R symmetry breaking mechanisms among animals.

Keywords: Nodal; evolution; left-right asymmetry; vertebrates.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Actomyosin / physiology*
  • Animals
  • Birds
  • Body Patterning*
  • Cell Polarity*
  • Cilia*
  • Embryo, Mammalian
  • Embryo, Nonmammalian
  • Embryonic Development*
  • Mice
  • Reptiles
  • Xenopus
  • Zebrafish

Substances

  • Actomyosin

Grants and funding

The work in the Hamada laboratory was supported by grants from CREST (Core Research for Evolutional Science and Technology of the Japan Science and Technology Corporation) (17H01435) and the Ministry of Education, Culture, Sports, Science and Technology of Japan (18K14725). PPLT is a Senior Principal Research Fellow of the National Health and Medical Research Council of Australia (NHMRC grant 1003100).