Cell sorting at D/V compartment boundary
Final Report Abstract
The formation of straight compartment boundaries separating cells with different fates or functions is important for proper tissue and organ development in animals. In Drosophila, the developing wing is initially subdivided into anterior and posterior compartments and subsequently into dorsal and ventral compartments. Our previous work had shown that the cell bonds along the anteroposterior compartment boundary are under increased actomyosin- dependent mechanical tension compared to cell bonds within the bulk of the tissue. Furthermore, simulations of tissue growth reveal that a local increase in cell bond tension suffices to maintain straight boundaries between compartments. Moreover, reduction of Myosin motor activity impairs compartment boundary shape. These data are consistent with a model in which a local increase in mechanical tension plays an important role in maintaining the characteristic straight shape of the anteroposterior compartment boundary. This project had two aims: First, to test whether a local increase in mechanical tension is a more common signature of compartment boundaries. Second, to reveal the mechanisms by which mechanical tension is locally increased along compartment boundaries. We have addressed both aims by using the dorsoventral compartment boundary in the developing Drosophila wing as a model system. We show by laser ablating single cell bonds and measuring the resulting tissue recoil that mechanical tension is increased along the dorsoventral compartment boundary. Moreover, by combining genetic mutants and laser ablation experiments, we were able to show that the selector gene apterous, which was previously known to specify dorsal identity in the developing wing, is required to increase mechanical tension at this compartment boundary. Furthermore, our experiments identify Notch, a signaling molecule important for the communication between dorsal and ventral cells, as a further important regulator of mechanical tension at the dorsoventral compartment boundary. Our work suggests that a local increase in mechanical tension is a common signature of compartment boundaries. Moreover, it provides insights into the developmental regulators that generate patterns of mechanical tension important for compartment boundary formation and tissue organization.
Publications
-
The selector gene apterous and Notch are required to locally increase mechanical cell bond tension at the Drosophila dorsoventral compartment boundary. PLoS ONE 11(8): e0161668, 2016
Michel, M., Aliee, A., Rudolf, K., Bialas, L., Jülicher, F., and Dahmann, C.
