A minimal vertex model explains how the amnioserosa avoids fluidization during Drosophila dorsal closure

• 成果类型: Article
• 署名作者: Tah, Indrajit; Haertter, Daniel; Crawford, Janice M.; Kiehart, Daniel P.; Schmidt, Christoph F.; Liu, Andrea J.
• 署名单位: Council of Scientific & Industrial Research (CSIR) - India; CSIR - Central Glass & Ceramic Research Institute (CGCRI); University of Pennsylvania; University of Gottingen; UNIVERSITY GOTTINGEN HOSPITAL; Duke University; Duke University; The Santa Fe Institute
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13400
• DOI: 10.1073/pnas.2322732121
• 发表日期: 2025-01-07
• 关键词: cell sheet morphogenesis; myosin-ii; forces; shape; mechanics; contraction; actomyosin; anisotropy; reveals; tension

摘要

Dorsal closure is a process that occurs during embryogenesis of Drosophila melanogaster. During dorsal closure, the amnioserosa (AS), a one-cell thick epithelial tissue that fills the dorsal opening, shrinks as the lateral epidermis sheets converge and eventually merge. During this process, both shape index and aspect ratio of amnioserosa cells increase markedly. The standard 2-dimensional vertex model, which successfully describes tissue sheet mechanics in multiple contexts, would in this case predict that the tissue should fluidize via cell neighbor changes. Surprisingly, however, the amnioserosa remains an elastic solid with no such events. We here present a minimal extension to the vertex model that explains how the amnioserosa can achieve this unexpected behavior. We show that continuous shrinkage of the preferred cell perimeter and cell perimeter polydispersity lead to the retention of the solid state of the amnioserosa. Our nonmonotonic junction tension that we confirm with laser ablation experiments.