Analysis and modeling of epithelial tissue organization during head involution stage of Drosophila embryogenesis

Abstract

Tissue biomechanics plays an important role in the progression of epidermal tissue dur- ing the head involution process of Drosophila embryogenesis. Understanding the self- organizing principles which are controlling the underlying segment width control by mod- ulations in the cellular shape pattern in such epithelial tissue spreading is necessary for identifying crucial factors in cell migration, tissue growth, and regeneration. We try to corroborate our experimental observations about pattern of periodic cell shapes and equal tissue segment width at the completion of the involution process with a 2D tissue sim- ulation setup using the Cellular Pott’s model (CPM). The model partially manages to recover some of the experimental data using only the physical parameters of cortical ten- sion along with providing an explanation for the variation in cell shapes and segment width seen in WT embryos. Further, following from previous published data, a correla- tion between Hh genes and junctional tension at the segmental boundary regions of the epithelial tissue organization during the head involution stage of embryogenesis can be modelled by incorporation of biochemical feedback into the CPM model. Implementation of a diffusion gradient of Hh and Wg incorporated with the cell mechanics of the Pott’s model is hypothesized to validate the findings of patterned contractile forces at the global tissue scale reported previously by Czerniak et al 2016.