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Mederacke, M.

Publications and source records attributed to Mederacke, M..

3 recordsLinked to original sources

Directed cell migration is a versatile mechanism for rapid developmental pattern formation

The evolution of multicellular organisms hinges on self-organization mechanisms that generate tissues with diverse functions. A central process is the breaking of symmetry to form spatial patterns from initially uniform conditions. Among the various mechanisms proposed, directed cell migration--driven by chemotaxis, durotaxis, differential adhesion or other processes--offers a compelling strategy to organize tissues rapidly and robustly. Here, we unify these concepts into a general mathematical framework and show that it can produce diverse spatial patterns across one-, two-, and three-dimensional domains. Using numerical simulations and stability theory, we characterize the emergence, geometry, and formation speed of these patterns. Our findings provide a mechanistic understanding of morphogenesis beyond the traditional chemical or mechanical patterning paradigms and offer a quantitative foundation to guide pattern formation in tissue engineering and regenerative medicine.

developmental biology↗

The emergence of the fractal bronchial tree

The fractal design of the bronchial tree, as described by the Hess-Murray law, facilitates energy-efficient lung ventilation, yet its developmental origins remain unclear. Here, we quantify the rearrangement of the embryonic bronchial tree into its fractal architecture, using SkelePlex, a new neural network-based image processing pipeline, and elucidate the biophysical principles governing its formation. We find that the branch shapes are such that pressure drop, shear, axial and hoop stress are equal across all branches. The seemingly random diameter of sister branches reflects the different number of tips they connect to in the asymmetric lung tree. By analysing lungs after pneumonectomy and those affected by chronic obstructive pulmonary disease (COPD), we show the same principles to persist in adulthood and disease, potentially providing quantitative biomarkers for disease progression and therapeutic guidance.

developmental biology↗

Geometric Effects Position Renal Vesicles During Kidney Development

During kidney development, reciprocal signalling between the epithelium and the mesenchyme coordinates nephrogenesis with branching morphogenesis of the collecting ducts. The mechanism that positions the renal vesicles, and thus the nephrons, relative to the branching ureteric buds has remained elusive. By combining computational modelling and experiments, we show that geometric effects concentrate the key regulator, WNT9b, at the junctions between parent and daughter branches where renal vesicles emerge, even when uniformly expressed in the ureteric epithelium. This curvature effect might be a general paradigm to create non-uniform signalling in development.

developmental biology↗