Robustness of the microtubule network self-organization in epithelia

Robustness of biological systems is crucial for their survival, however, for many systems its origin is an open question. Here, we analyze one subcellular level system, the microtubule cytoskeleton. Microtubules self-organize into a network, along which cellular components are delivered to their biologically relevant locations. While the dynamics of individual microtubules is sensitive to the organism’s environment and genetics, a similar sensitivity of the overall network would result in pathologies. Our large-scale stochastic simulations show that the self-organization of microtubule networks is robust in a wide parameter range in individual cells. We confirm this robustness in vivo on the tissue-scale using genetic manipulations of Drosophila epithelial cells. Finally, our minimal mathematical model shows that the origin of robustness is the separation of time-scales in microtubule dynamics rates. Altogether, we demonstrate that the tissue-scale self-organization of a microtubule network depends only on cell geometry and the distribution of the microtubule minus-ends.

Please outline where this information can be found within the submission (e.g., sections or figure legends), or explain why this information doesn't apply to your submission: The minimum sample size was estimated based on the mean values and the standard deviation of a control set of embryos to allow detection of differences of 10% in the means, in a pair-wise comparison, with a power of 0.8 and α 0.05 (using http://powerandsamplesize.com/ and was 7 embryos). As standard deviations were larger for some genotypes, we aimed for 15 embryos per genotype. Previous empirical evidence by N.A.B. suggests that the used sample sizes are sufficient to detect the biologically significant differences.

Replicates
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Statistical reporting
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Please outline where this information can be found within the submission (e.g., sections or figure legends), or explain why this information doesn't apply to your submission: Raw data is presented in figures in a form of dot plots and graphs (Figures 4,5,7,8,and in  (For large datasets, or papers with a very large number of statistical tests, you may upload a single table file with tests, Ns, etc., with reference to sections in the manuscript.)

Group allocation
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