Biology subjects

Eaton, S.

Publications and source records attributed to Eaton, S..

3 recordsLinked to original sources

bioRxiv2018

Mechanosensitive binding of p120-Catenin at cell junctions regulates E-Cadherin turnover and epithelial viscoelasticity

Studying how epithelia respond to mechanical stresses is key to understanding tissue shape changes during morphogenesis. Here, we study the viscoelastic deformation of the Drosophila pupal wing epithelium in response to mechanical stress that evolves during morphogenesis. We show that wing epithelial tissue viscoelasticity depends on endocytic turnover of E-Cadherin. The fraction of ECadherin undergoing turnover depends on mechanical stress in the epithelium. We identified mechanosensitive binding of the endocytic regulator p120-Catenin (p120) as a mechanism to regulate E-Cadherin turnover. Under high stress, p120 is released into the cytoplasm, destabilizing E-Cadherin complexes and increasing its turnover. In p120 mutants, E-Cadherin turnover is insensitive to mechanical stress. Furthermore, we show that p120 is crucial for the viscoelastic deformation of the wing epithelium. Taken together, our findings reveal that mechanosensitive binding of p120-Catenin tunes epithelial tissue viscoelasticity during morphogenesis.

biophysics↗

bioRxiv2018

Rab-mediated trafficking in the secondary cells of Drosophila male accessory glands and its role in fecundity

It is known that the male seminal fluid contains factors that affect female post-mating behavior and physiology. In Drosophila, most of these factors are secreted by the two epithelial cell types that make up the male accessory gland: the main and secondary cells. Although secondary cells represent only 4% of the cells of the accessory gland, their contribution to the male seminal fluid is essential for sustaining the female post-mating response. To better understand the function of the secondary cells, here we investigate their molecular organization, particularly with respect to the intracellular membrane transport machinery. We determined that large vacuole-like structures found in the secondary cells are trafficking hubs labeled by Rab6, 7, 11 and 19. Furthermore, these cell-specific organelles are essential for the long-term post-mating behavior of females and that their formation is directly dependent upon Rab6. Our discovery adds to our understanding of Rab proteins function in secretory cells. We have created an online, open-access imaging resource as a valuable tool for the intracellular membrane and protein traffic community.

cell biology↗

bioRxiv2017

Cell Dynamics Underlying Oriented Growth Of The Drosophila Imaginal Wing Disc

Quantitative analysis of the dynamic cellular mechanisms shaping the Drosophila wing during its larval growth phase has been limited, impeding our ability to understand how morphogen patterns regulate tissue shape. Such analysis requires imaging explants under conditions that maintain both growth and patterning, as well as methods to quantify how much cellular behaviors change tissue shape. Here, we demonstrate a key requirement for the steroid hormone 20-hydroxyecdysone (20E) in the maintenance of numerous patterning systems in vivo and in explant culture. We find that low concentrations of 20E support prolonged proliferation in explanted wing discs in the absence of insulin, incidentally providing novel insight into the hormonal regulation of imaginal growth. We use 20E-containing media to directly observe growth and apply recently developed methods for quantitatively decomposing tissue shape changes into cellular contributions. We discover that while cell divisions drive tissue expansion along one axis, their contribution to expansion along the orthogonal axis is cancelled by cell rearrangements and cell shape changes. This finding raises the possibility that anisotropic mechanical constraints contribute to growth orientation in the wing disc.

developmental biology↗