Presentation Information
[C02-05]Bilateral cellular flow displays left-right asymmetry in avian gastrulation
*Rieko Asai1,2, Shubham Sinha3, Vivek N Prakash3, Takashi Mikawa2 (1. Kumamoto University (Japan), 2. UCSF (United States of America), 3. University of Miami (United States of America))
Keywords:
Left-right asymmetry,Cellular flow,Gastrulation,PIV analysis,Chick
Most animals (including human, mice and birds) show outer left-right (LR)-symmetry with inner LR-asymmetry. A fundamental question in animal development is when and how the LR-asymmetry is established. While expression patterns of laterality genes after formation of the LR-organizer, which serves as a signaling center for LR-patterning, have been extensively studied, the origin of LR-asymmetry in the embryo has remained unclear. By using biophysical approaches, we found that LR-asymmetric patterning of cellular flows has initiated much earlier than the current model predicts during amniote development. In chick embryos, a bilateral counter-rotating cellular flow, termed ‘polonaise movements’, occurs along the midline axis during primitive streak development, which is the earliest midline structure. Our experimental system combined with PIV analysis quantified LR-asymmetric parameters in the polonaise movements (Asai and Sinha et al., PNAS, 2025). These results suggest that physical processes may play a significant role in influencing LR asymmetric body patterning.