Axolotls are uniquely able to resolve spinal cord injuries, but little is known about the mechanisms underlying spinal cord regeneration. We previously found that tail amputation leads to reactivation of a developmental-like program in spinal cord ependymal cells (Rodrigo Albors et al., 2015), characterized by a high-proliferation zone emerging 4 days post-amputation (Rost et al., 2016). What underlies this spatiotemporal pattern of cell proliferation, however, remained unknown. Here, we use modelling, tightly linked to experimental data, to demonstrate that this regenerative response is consistent with a signal that recruits ependymal cells during ~85 hours after amputation within ~830mm of the injury. We adapted FUCCI technology to axolotls (AxFUCCI) to visualize cell cycles in vivo. AxFUCCI axolotls confirmed the predicted appearance time and size of the injury-induced recruitment zone and revealed cell cycle synchrony between ependymal cells. Our modeling and imaging move us closer to understanding bona fide spinal cord regeneration.
Jupyter Notebook (http://jupyter.org/) containing the source code for all computations performed and referred to as Cura Costa et al., 2021 in this study can be found at https://doi.org/10.5281/zenodo.4557840
- Osvaldo Chara
- Osvaldo Chara
- Osvaldo Chara
- Emanuel Cura Costa
- Elly M Tanaka
- Leo Otsuki
- Aida Rodrigo Albors
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: The licenses necessary for work with genetically modified organisms (GMOs) and for experiments specifically involving axolotls (Ambystoma mexicanum) were obtained from the relevant authorities and have been implemented at the IMP in accordance with applicable international, EU and national (Austrian) guidelines.The license for work with GMOs at safety levels 1 and 2 was approved by the GMO office of the Austrian authorities and was issued on 16/03/2017 with no end date (BMGF‐76110/0017‐ II/B/16c/2017).The axolotl research license numbers are GZ: 51072/2019/16 (valid 09/05/2019 - 28/02/2024) and GZ: MA58/665226/2019/21 (valid 24.02.2020 - 30.09.2024). These are approved by the City of Vienna, MA58.There is a dedicated veterinarian for the animal facility, as well as an animal welfare consultant. Animal facility inspections are performed yearly by the City of Vienna, MA58 and the animal licenses and animal husbandry conditions are updated in dialogue with animal welfare authorities.Axolotls (Ambystoma mexicanum) were raised in individual aquaria. Axolotl breedings were performed by the IMP animal facility. All experiments were performed in accordance with locally applicable ethics committee guidelines and within a framework agreed with the Magistrate of Vienna (Austria). Axolotls were anaesthetized with benzocaine (Sigma) diluted in tap water prior to amputation and/or imaging, to minimize suffering.
- Alejandro Sánchez Alvarado, Stowers Institute for Medical Research, United States
- Received: February 10, 2020
- Accepted: May 13, 2021
- Accepted Manuscript published: May 14, 2021 (version 1)
© 2021, Cura Costa et al.
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