The mesentery as the epicenter for intestinal regeneration

•Cellular changes in the mesentery occur soon after evisceration.•These changes give rise to cellular precursors that form the new intestinal rudiment.•Muscle dedifferentiation and cellular proliferation are the main mechanisms of the regeneration process.•Other mechanisms involve apoptosis, extracellular matrix remodeling and epithelial to mesenchymal transitions.•Major changes in gene expression profiles accompany the regeneration event. The mesentery, a newly minted organ, plays various anatomical and physiological roles during animal development. In echinoderms, and particularly in members of the class Holothuroidea (sea cucumbers) the mesentery plays an additional unique role: it is crucial for the process of intestinal regeneration. In these organisms, a complete intestine can form from cells that originate in the mesentery. In this review, we focus on what is known about the changes that take place in the mesentery and what has been documented on the cellular and molecular mechanisms involved. We describe how the events that unfold in the mesentery result in the formation of a new intestine.