Figure 1

Stages of intestinal regeneration in H. glaberrima. (A) Diagram showing the relationship of the intestinal rudiment (brackets) to the mesentery and body wall (BW). The mesentery is divided into three sections: Proximal to the body wall (PM), medial mesentery (MM) and adjacent to the rudiment (AM). Transverse tissue sections of mesentery and regenerating intestine at (B) 1-, (C) 3-, (D) 5-, (E) 7- and (F) 10-days post evisceration (dpe) were stained with Toluidene Blue. (B) At 1-dpe the coelomic epithelium covers the tip of the mesentery but there is no clear thickening. (C) By 3-dpe, a small enlargement can be observed at the mesenterial tip. (D) By 5-dpe the intestinal rudiment has increased considerably in size and some areas of the mesothelium appear to have an increased number of cells (brackets) when compared to the 1-day mesentery (see brackets in Figure 1B). (E) By 7-dpe the rudiment has acquired a pear-shaped morphology and the appendix at the tip (arrowhead) is evident (F) At 10-dpe the lumen has formed and all tissue layers of the mature intestine can be found within the rudiment. Arrows signal the boundary between the forming intestinal rudiment and the mesentery. Bar = B-C 25 μm, D 50 μm, E&F 100 μm