Regensburg 2025 – scientific programme
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BP: Fachverband Biologische Physik
BP 18: Tissue Mechanics
BP 18.9: Talk
Wednesday, March 19, 2025, 12:00–12:15, H44
A mechanical model of the symmetry breaking of the shape of the primordial hindgut — Daniel S. Alber1,2, Shiheng Zhao3,4,5, Eric F. Wieschaus2,6, Stanislav Y. Shvartsman2,6,7, and •Pierre A. Haas3,4,5 — 1Department of Chemical and Biological Engineering, Princeton University — 2Lewis-Sigler Institute for Integrative Genomics, Princeton University — 3Max Planck Institute for the Physics of Complex Systems — 4Max Planck Institute of Molecular Cell Biology and Genetics — 5Center for Systems Biology Dresden — 6Department of Molecular Biology, Princeton University — 7Center for Computational Biology, Flatiron Institute
During early Drosophila morphogenesis, as the germband extends and the midgut invaginates, the initially circular primordial hindgut moves from the posterior pole of the embryo to its dorsal side and folds into a characteristic keyhole shape. Here, we develop a minimal model of this symmetry breaking in which the hindgut appears as an inextensible elastic ring in the plane. We discover that, as the area enclosed by the ring decreases (midgut invagination) while a diameter is held fixed (germband extension), the circular shape bifurcates robustly into the observed keyhole shape. Moreover, we show how embryonic curvature breaks symmetry further to select the observed orientation of the keyhole shape. This demonstrates that morphogenesis of the primordial hindgut can be a passive mechanical consequence of active deformations of the tissues that surround it.
Keywords: Morphogenesis; Mechanical bifurcation; Drosophila