Chiral Cilia Orientation in the Left-Right Organizer

• Published in: Cell reports (Cambridge) Vol. 25; no. 8; pp. 2008 - 2016.e4
• Main Authors: Ferreira, Rita R., Pakula, Guillaume, Klaeyle, Lhéanna, Fukui, Hajime, Vilfan, Andrej, Supatto, Willy, Vermot, Julien
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20-11-2018; Elsevier
• Subjects: Animals; Basal Bodies - metabolism; blebbistatin; Body Patterning; Cilia - metabolism; Danio rerio; Development Biology; Dnaaf1/Lrrc50; Life Sciences; lrdr1; nodal; Organizers, Embryonic - physiology; PKD2/PC2/TRPP2/polycistin-2; Rock2B; spaw; tissue asymmetry; trilobite/Vangl2; Zebrafish - embryology; Zebrafish Proteins - metabolism; Dnaaf1/Lrrc50; trilobite/Vangl2; PKD2/PC2/TRPP2/polycistin-2; spaw; tissue asymmetry; Danio rerio; lrdr1; nodal; Rock2B; blebbistatin
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2018.10.069

Chirality is a property of asymmetry between an object and its mirror image. Most biomolecules and many cell types are chiral. In the left-right organizer (LRO), cilia-driven flows transfer such chirality to the body scale. However, the existence of cellular chirality within tissues remains unknown. Here, we investigate this question in Kupffer’s vesicle (KV), the zebrafish LRO. Quantitative live imaging reveals that cilia populating the KV display asymmetric orientation between the right and left sides, resulting in a chiral structure, which is different from the chiral cilia rotation. This KV chirality establishment is dynamic and depends on planar cell polarity. While its impact on left-right (LR) symmetry breaking remains unclear, we show that this asymmetry does not depend on the LR signaling pathway or flow. This work identifies a different type of tissue asymmetry and sheds light on chirality genesis in developing tissues.
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•KV cilia display asymmetric orientation between the right and left sides•Cilia orientation depends on PCP, but does not directly follow its direction•Impact of asymmetric cilia orientation on left-right symmetry breaking is unclear•Asymmetric cilia orientation is independent of left-right signaling pathway or flow
During left-right axis specification, motile cilia are required for breaking the axis of symmetry. In this context, Ferreira et al. show that cilia orientation is chiral, defining an alternative type of asymmetry in the embryo.