Mechanical waves identify the amputation position during wound healing in the amputated zebrafish tailfin
For over 250 years, biologists have been puzzled by why highly regenerative animals regrow lost appendages at the rate that is proportional to the amount of appendage loss. A team led by Dr. Chen-Hui Chen at the Institute of Cellular and Organismic Biology (ICOB) and Dr. Keng-Hui Lin at the institute of physics (IOP) discovered a ‘mechanical wave’ that governs positional sensing during wound healing and regeneration. This unexpected finding has been published in the journal Nature Physics in June 2023.
Highly regenerative animals can regrow lost appendages and the rate of regrowth is proportional to the amount of appendage loss. This century-old phenomenon prompted us to to investigate whether the mechanism of wound healing, as the first stage of regeneration, is responsible for discerning the amputation position. In vitro studies have revealed significant insights into the mechanics of the wound-healing process, including the identification of mechanical waves in collective epithelial cell expansion. It has been suggested that these mechanical waves may also be involved in positional sensing. Here, we perform live-cell imaging on adult zebrafish tailfins to monitor the collective migration of basal epithelial cells upon tailfin amputation. We observed a cell density wave propagating away from the amputation edge, with the maximum traveling distance proportional to the amputation level and cell proliferation at later stages. We developed a mechanical model to explain this wave behaviour, including the tension-dependent wave speed and amputation-dependent traveling distance. Together, our findings point to an in vivo positional sensing mechanism in regenerative tissue based on a coupling of mechanical signals manifested as a traveling density wave.
This study is supported by funding from the Institute of Cellular and Organismic Biology and the Institute of Physics, Academia Sinica, to C.-H.C. and K.-H.L.; grants from Academia Sinica to C.-H.C. (AS-CDA-109-L03) and the Academia Sinica Innovative Materials and Analytical Technology Exploration Program to K.-H.L. (AS-iMATE-109-12 and AS-iMATE-111-14); and grants from National Science and Technology Council, Taiwan, to C.-H.C. (MOST 106-2628-B-001-001-MY4 and MOST 110-2628-B-001-016), K.-H.L. (MOST 109-2122-M-001-001-MY2), and F.-L.W. (MOST 109-2112-M006-028-MY3).
Author list: Marco P. De Leon, Fu-Lai Wen, Giovanni J. Paylaga, Ying-Ting Wang, Hsiao-Yuh Roan, Chung-Han Wang, Chung-Der Hsiao, Keng-Hui Lin*, and Chen-Hui Chen*
(*Corresponding authors)
Article title: Mechanical waves identify the amputation position during wound healing in the amputated zebrafish tailfin
Article(Nature Physics) link: https://www.nature.com/articles/s41567-023-02103-6
