Noah Mitchell - Mapping the Mechanics and Dynamics of Gut Morphogenesis; Stefan Harmansa - Shaping Growing Tissues by Basement Membrane Mechanics

Add to your list(s) Download to your calendar using vCal

• Noah Mitchell - University of Chicago & Stefan Harmansa-Living Systems Institute - University of Exeter United Kingdom
• Monday 04 November 2024, 14:30-15:30
• Online.

If you have a question about this talk, please contact Jia CHEN.

Noah Mitchell

Mapping the Mechanics and Dynamics of Gut Morphogenesis

Abstract: During embryonic development, the gut transforms from laminar tissue sheets into a closed tube, sculpts distinct compartments along its long axis, and coils into a chiral shape. I will present ongoing work on understanding the mechanics by which these three morphogenetic events unfold in the embryonic Drosophila midgut. A computational toolkit, TubULAR, plays a central role by parameterizing the complex tissue deformations involved and enabling whole-organ characterization of the dynamics.

Shaping Growing Tissues by Basement Membrane Mechanics

Stefan Harmansa

Abstract: Growing tissues are constantly exposed to mechanical stresses that lead to deformations on the cell and tissue level shaping the 3-dimensional morphology of developing tissues. Stresses can originate from cellular activity within a tissue or from mechanical interactions with surrounding structures. I will first consider stresses that originate from a growth difference (anisotropy) between epithelial tissues and their surrounding basement membrane (BM). I will subsequently explore how the mechanical interplay between epithelial growth, basement membrane mechanics and tissue-extrinsic stresses guides cell and tissue shape during Drosophila wing disc morphogenesis.

The wing disc is a flattened, epithelial cyst consisting of two tissue layers, the columnar disc proper epithelium (DP) and the squamous peripodial epithelium (PPE). We have previously shown that a differential anisotropy in growth between the DP tissue and its BM drives the bending of the wing disc in a tissue-autonomous manner. In addition, the stresses originating from DP bending are essential in shaping the morphology of the overlaying PPE layer. Notably, the mechanic response of the PPE to this tissue-external bending stress is non-uniform in space: While central PPE cells flatten and obtain a squamous morphology in response to the tensile bending stress, the peripheral PPE cells obtain a columnar shape. These inverse shape transitions originate from differences in BM mechanics, where a fluid-like BM allows elastic deformation of the central PPE cells while a ridged BM shields peripheral PPE from this tensile bending stress. These inverse shape transitions are further amplified by selective shearing of the central cells due to epithelial coupling via the apical extracellular matrix protein Dumpy. In summary, I will show how the interplay of tissue intrinsic BM properties and external forces orchestrate cell shape transitions during multilayered epithelial morphogenesis.

Join the Zoom with the link: https://cam-ac-uk.zoom.us/j/87503254733 Meeting ID: 875 0325 4733

This talk is part of the Morphogenesis Seminar Series series.

This talk is included in these lists:

• Graduate-Seminars
• Morphogenesis Seminar Series
• Online

Note that ex-directory lists are not shown.