arXiv subjects

Rodrigo Fernandez-Gonzalez

Publications and source records attributed to Rodrigo Fernandez-Gonzalez.

3 recordsLinked to original sources

arXiv2026

Cell intrinsic dynamics guide neuroblast ingression independent of tissue fluidity

Morphogenesis involves the coordination of multiple cellular processes that occur simultaneously within developing tissues. During early Drosophila embryogenesis, neuroblast (NB) ingression occurs concurrently with germ band extension (GBE), yet whether these processes interact mechanistically remains unclear. Here, we combine mathematical modelling with quantitative live imaging to investigate whether tissue-level mechanics during GBE influence NB ingression dynamics. Mathematical modelling predicted that reducing tissue fluidity through impaired cellular rearrangements should slow NB ingression by increasing mechanical resistance. Experimental analysis of mutants in which cell intercalation and GBE are disrupted revealed a dramatic reduction in tissue fluidity. However, NB ingression rates remained largely unaffected when tissue fluidity decreased. Incorporating cell-intrinsic myosin anisotropy and endocytosis-contractility coupling into our mathematical model rescued the rate of neuroblast ingression in solid-like tissues. Thus, our findings suggest that cell-intrinsic mechanisms, rather than tissue-level fluidity, maintain ingression kinetics. More broadly, these results illustrate how developmental systems can achieve robustness by insulating critical cellular events from tissue-level mechanical variability.

physics.bio-ph↗

arXiv2026

Cell Behavior Video Classification Challenge, a benchmark for computer vision methods in time-lapse microscopy

The classification of microscopy videos capturing complex cellular behaviors is crucial for understanding and quantifying the dynamics of biological processes over time. However, it remains a frontier in computer vision, requiring approaches that effectively model the shape and motion of objects without rigid boundaries, extract hierarchical spatiotemporal features from entire image sequences rather than static frames, and account for multiple objects within the field of view. To this end, we organized the Cell Behavior Video Classification Challenge (CBVCC), benchmarking 35 methods based on three approaches: classification of tracking-derived features, end-to-end deep learning architectures to directly learn spatiotemporal features from the entire video sequence without explicit cell tracking, or ensembling tracking-derived with image-derived features. We discuss the results achieved by the participants and compare the potential and limitations of each approach, serving as a basis to foster the development of computer vision methods for studying cellular dynamics.

eess.IV↗

arXiv2025

Cell divisions both challenge and refine tissue boundaries in the Drosophila embryo

Tissue boundaries pattern embryos, suppress tumours, and provide directional cues. Tissue boundaries are associated with supracellular cables formed by actin and the molecular motor non-muscle myosin II. Actomyosin cables generate tension that prevents cell mixing. Whether other cellular behaviours contribute to the formation of linear interfaces between cell populations remains unclear. In the Drosophila embryo, an actomyosin-based boundary separates the ectoderm from the mesectoderm, a group of neuronal and glial progenitors. Mathematical modelling predicted that cell divisions in the ectoderm challenge the mesectoderm-ectoderm (ME) boundary. Consistent with this, suppressing ectoderm cell divisions in vivo prevented cell mixing across the ME boundary when actomyosin-based tension was lost. Our mathematical model also predicted that cell divisions sharpen the ME boundary by reducing tension and increasing cell motility in the ectoderm. We found that inhibiting ectoderm divisions in vivo reduced boundary linearity. Using laser ablation and cell tracking, we demonstrated that cell divisions reduced junctional tension and increased cell movement in the ectoderm. Together, our results reveal that cell divisions facilitate cellular rearrangements to increase fluidity in a novel mechanism for boundary refinement.

physics.bio-ph↗