Development recently published a study on regeneration in the marine worm
Platynereis dumerilii. Just a few inches long (a few centimeters), this worm has a remarkable ability to regenerate entire parts of its body within days following an injury or amputation.
The research team, led by a scientist from the CNRS, focused on the mechanisms involved in the regeneration of the worm's tail. They discovered that intestinal cells play a crucial role not only in regenerating the intestine but also in regenerating other tissues such as muscles and the epidermis. Even more surprisingly, this ability of intestinal cells to regenerate different types of tissues varies depending on their location: the closer the cells are to the worm's posterior end, the more they can contribute to the regeneration of a variety of tissues.
To make these observations, the scientists tracked the fate of intestinal cells and proliferating cells at the amputated end. They used various markers, including the ingestion of fluorescent beads by the worms, to trace these cells. For about twenty years, annelids, or "segmented worms," have been a model of choice for studying regeneration, a process still mysterious to researchers despite its widespread occurrence among animals.
The results of this study reveal that regeneration is partially promoted by a population of proliferative intestinal cells whose regenerative potential varies according to their position along the worm's antero-posterior axis. Intestinal progenitors from anterior tissues are limited to a single lineage, while those from posterior tissues are more proliferative and significantly more plastic. However, they cannot regenerate the stem cells responsible for the growth of the worms, as these stem cells are of local origin and derive from cells present in the segment adjacent to the amputated area.
The research team continues its work to determine if other types of cells, aside from intestinal cells, participate in the regeneration of different cell types. This study highlights a hybrid and flexible cellular model for posterior regeneration in
Platynereis dumerilii, relying on varying degrees of cellular plasticity.
Article by: Cédric DEPOND