Regeneration has long been the focus of scientific interest for its potential to restore lost, damaged, or aged tissues and organs. A wide range of regenerative studies have been conducted on different vertebrate and invertebrate model organisms. Annelids are known for their regenerative capacities, and because of their relatively complex organ systems, they are an ideal organism for regeneration study. Our present work focused on the freshwater annelid Aeolosoma viride, an asexually reproducing annelid capable of regenerating both anteriorly and posteriorly. Even though regenerative ability has been documented in this animal in previous studies, detailed characterization of the process is still unavailable. The objective of this study was to evaluate the regenerative ability of A. viride. We described the sequential morphological events during the process of regeneration, such as wound healing and the formation of blastema, mouth, and pygidium. In order to clarify the capacity and type of regeneration, we conducted a series of observations and experiments using a cell proliferation assay. Massive proliferation and the absence of cell migration indicated that the animal regenerates primarily through epimorphosis. Our study of the epimorphic regenerative process of A. viride provides a clearer picture of the evolutionary origin of regeneration in annelids.
Wing fok, chiao-ping chen, tzu-Lun tseng, Yi-Hua chiang & Jiun-Hong chen ✉ Although apoptosis has been widely observed during the regenerative process, the mechanisms by which it is regulated and its roles in regeneration remained unclear. in this study, we introduced Aeolosoma viride, a fresh water annelid with an extraordinary regenerative ability as our model organism to study the functions and regulations of apoptotic caspases. Here we showed that major events of apoptosis were detected near the wounded area and showed spatial correlation with the expression patterns of caspase gene namely Avi-caspase X and two apoptosis regulators namely Avi-Bax and Avi-Bcl-xL. next, we investigated how Avi-caspase X gene expression and apoptosis influence regeneration following head amputation. RnA interference of Avi-caspase X reduced the amounts of apoptotic cells, as well as the percentage of successful regeneration, suggesting a critical role for apoptosis in anterior regeneration of A. viride. in addition, we also discovered that the expression of apoptotic caspases was regulated by the canonical Wnt signaling pathway. together, our study showed that caspase dependent apoptosis was critical to the anterior regeneration of A. viride, and could be regulated by the canonical Wnt signaling pathway. Aeolosoma viride is a fresh water annelid that can regenerate both anteriorly and posteriorly within 5 days after amputation 1. Amputation created a rough and uneven wounded area that smoothened around 12 hours post amputation (hpa). After 12 hpa, a hyaline cell masses started to develop at the regenerating area which characterized blastema formation. Mouth formation was initiated around 96 hpa, in which a circular structure reappeared at the ventral side of the peristomium. After 96 hpa, the anterior regenerating head bulged and became wider than posterior segments. Most worms are freely to move at 120 hpa, which was considered as a successful anterior regeneration 2. Previous studies showed that cell proliferation is required for the formation of blastema in A. viride 2. Similar to many animal species, undifferentiated cells from the blastema can proliferate and differentiate in an orderly manner to replace the missing body parts, tissues or organs in this annelid 3-5. Since many multicellular organisms maintain an appropriate body size, cell proliferation must be coordinated with other biological processes. One of such mechanisms is apoptosis 6. Apoptosis is a form of programmed cell death that eliminates cells that are damaged or no longer required in a coordinated manner 7. In many organisms, apoptosis is a normal and essential part of development. Studies have confirmed that apoptosis is necessary for the proper development of many organisms for it affect a wide range of biological processes 8-11. Organs and tissues that are only useful during the embryonic stage are eliminated by apoptosis to allow further development. Coordinated apoptosis on a large group of cells provide a mean to shape interdigital tissue in many vert...
Aeolosoma viride, a globally distributed freshwater annelid, has a semitransparent appearance with 10 to 12 segments, about 2 to 3 mm in length. It is easy to raise and handle in laboratory conditions. Due to its robust regenerative capacity and applicability of various molecular tools including EdU labeling, whole-mount in situ hybridization (WISH), and RNA interference (RNAi), it rises as a promising model for studying whole-body regeneration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.