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Yanakieva, I.

Publications and source records attributed to Yanakieva, I..

2 recordsLinked to original sources

Cell shape noise strength regulates shape dynamics during EMT-associated cell spreading

Cellular shape is intimately linked to cell function and state, and transitions between cell states are tightly coupled to shape changes. Yet, shape has been largely overlooked in state transitions studies. Here, we combine morphometric analysis with theoretical modeling and molecular perturbations to interrogate cell shape dynamics during epithelial-to-mesenchymal transition (EMT). Using stochastic inference, we extract the morphogenetic landscape underlying EMT. We show that within this landscape, EMT-associated cell spreading reflects a transition between shape attractors. Strikingly, we observe a peak in cell shape noise strength concomitant with spreading, and show that higher shape noise accelerates transitions between shape attractors. Our morphometric analysis framework will be widely applicable to quantitative cell shape investigations in physiology and disease. Together, our results identify a key role for cellular stochasticity as a regulator of shape change rate, and highlight that shape dynamics yield rich phenotypic information that enhances our understanding of cellular states.

biophysics↗

Tissue shape determines actin-dependent nuclear migration mechanisms in neuroepithelia

Correct nuclear position is crucial for cellular function. Depending on cell context however, cytoskeletal elements and force generation mechanisms vary. While these mechanisms have been intensely studied in single cells, how nuclear positioning is linked to tissue morphology is less clear. Here, we compare apical nuclear positioning in developing straight and curved neuroepithelia of zebrafish. Interestingly, in differently shaped neuroepithelia the kinetics of nuclear positioning differ and we find that distinct actin-dependent mechanisms are employed. In straight neuroepithelia nuclear positioning is controlled by Rho-ROCK-dependent myosin contractility. Curved neuroepithelia use a formin-dependent pushing mechanism for which we propose a force generation theory. We suggest that cytoskeleton adaptability to tissue shape ensures correct nuclear positioning and robust epithelial maturation across different geometries. We further speculate that different mechanisms arise due to differences in actin arrangements during development, a theme highlighting the importance of developmental context for the execution of intracellular processes.

cell biology↗