The Link between Autotomy and CNS Regeneration: Echinoderms as Non‐Model Species for Regenerative Biology

Abstract

Achieving regeneration of the central nervous system (CNS) is a major challenge for regenerative medicine. The inability of mammals to regrow a severed CNS contrasts with the amazing regenerative powers of their deuterostome kin, the echinoderms. Rapid CNS regeneration from a specialized autotomy plane in echinoderms presents a highly tractable and suitable non‐model system for regenerative biology and evolution. Starfish arm autotomy triggers mass cell migration and local proliferation, facilitating rapid CNS regeneration. Many regeneration events in nature are preceded by autotomy and there are striking parallels between autotomy and regeneration in starfish and lizards. Comparison of these systems holds promise to provide insight into regeneration deficiency in higher vertebrates and to uncover evolutionarily conserved deuterostome‐chordate regenerative processes. This will help identify mechanisms that may be present but inactive in higher vertebrates to address the problem of their poor regenerative capacities and the challenge to achieve CNS repair and regrowth.

Population size structure and abnormalities in the number of rays of the Sea Star Pentaceraster cumingi (Valvatida: Oreasteridae) in Bahía Chamela, Mexican Pacific

“…The most common cause seems to be by regeneration process (Hotchkiss, 1979). Incidence of mutilation in some starfish has been suggested by fishing gears (Ramsay et al, 2001;Byrne, 2020). It is not considered in this study because the population studied was located inside a protected area where fishing activities are not allowed.…”

“…Regeneration is a common phenomenon in all actual echinoderm classes (Yousra et al, 2018;Byrne, 2020). It has been particularly well-studied in asteroids, where three main aspects have been identified: 1) regeneration of body parts (arms) following self-induced or traumatic amputation; 2) regeneration of internal organs (pyloric caeca and cardiac stomach) following self-induced or traumatic mutilation, and 3) fission processes (Candia-Carnevali, 2006).…”

Morphogenesis and histogenesis during the arm regeneration in a basket star Astrocladus dofleini (Euryalida, Ophiuroidea, Echinodermata)

“…In some studies of arm regeneration in brittle stars and starfish, clustered undifferentiated cells in regenerating arm tips were recognized by detailed microscopic observations including TEM, and those growth buds are referred as “blastema” (e.g., Biressi et al, 2010; Byrne, 2020). On the other hand, our study focused on the regenerative (and branching) process of arms of Astrocladus dofleini , and did not confirm that the cells clustered at the regenerating arm tip was undifferentiated.…”

“…Byrne et al (2019) induced autotomy of arms in Coscinasterias muricate , observed the regeneration process, especially focusing on cellular behavior in the tissue by immunostaining (e.g., increased glial cells). This study also insisted that the induction of autotomy, rather than artificial arm amputation, is important for observing natural arm regeneration process (Byrne, 2020; Byrne et al, 2019; Wilkie, 1978, 2001). In sea feathers (Crinoidea), Shibata, Oji, Akasaka, and Agata (2010) described the histological process of arm regeneration and subdivided it into nine phases, which were similar to those of ophiuroids.…”

“…Although some histological studies of arms were carried out in a basket star Gorgonocephalus caputmedusae (Rosenberg et al, 2005) and a snake star (euryalid ophiuroids with simple arms) Astrobrachion constrictum (Stewart, 2000), no studies have so far been performed on the regenerative processes in euryalid ophiuroids. In other echinoderms, the regeneration process of arms of asteroids have been histologically described, focusing on soft tissues (Byrne, 2020; Byrne, Mazzone, Elphick, Thorndyke, & Cisternas, 2019; Khadra et al, 2017), or on skeletal ossicles (Fau, 2018). Byrne et al (2019) induced autotomy of arms in Coscinasterias muricate , observed the regeneration process, especially focusing on cellular behavior in the tissue by immunostaining (e.g., increased glial cells).…”