Dynamically Evolving Cell Sizes During Early Development Enable Normal Gastrulation Movements In Zebrafish Embryos

Abstract

36Current knowledge of the mechanisms of cell migration is based on differentiated cells in 37 culture where it is known that the actomyosin machinery drives migration via dynamic 38 interactions with the extracellular matrix and adhesion complexes. However, unlike 39 differentiated cells, cells in early metazoan embryos must also dynamically change cell 40 sizes as they migrate. The relevance of cell size to cell migration and embryonic 41 development is not known. Here we investigate this phenomena in zebrafish embryos, a 42 model system in which reductive cell divisions causes cell sizes to decrease naturally over 43 time as cells migrate collectively to sculpt the embryonic body plan. We show that cell size 44 reduction during early development follows power-law scaling. Because mutations that 45 can perturb cell sizes so early in development do not exist, we generate haploid and 46 tetraploid zebrafish embryos and show that cell sizes in such embryos are smaller and 47 60 61

Continuum descriptions of spatial spreading for heterogeneous cell populations: Theory and experiment

“…This is an important consideration because it is wellknown that parameterising mathematical models of biological processes can be challenging, often requiring computationally-intensive methods (Pozzobon and Perré, 2018;Warne et al 2019). Although heterogeneity in cell populations is frequently observed in experiments, there is relatively little guidance or consensus in the literature about how to incorporate such heterogeneity into the mathematical models used to replicate and predict such experiments (An et al, 2001;Altschuler et al, 2010;Menon et al, 2018). Figure 1(a)-(b) shows a typical experiment where we can clearly visually observe cells of different sizes.…”