Figure 1
From: Mechanical Tension Drives Elongational Growth of the Embryonic Gut
The embryonic gut loop is in a state of longitudinal mechanical tension. (a) Top-view of E9 chicken embryo in-ovo, lying on its side. Black line: midline of the gut (white arrowhead: jejunum). The gut herniates out of the body, through the umbilical cord. Black arrowhead: attachment at the umbilicus of the omphalomesenteric artery (OMA) and vitelline duct (VD), which extend to the right into the yolk sac. (b) The gut (E8) spontaneously coils up when tensile forces are released after dissection. (c) Measurement of the force required to uncoil the gut. The black arrow points at the upper pin that holds the stomach and hindgut. (d) After removal of the mesentery, three permanent bends (red curved lines) are visible at the level of the hindgut, umbilicus and jejunum-duodenum junction. ST: stomach, DUOD: duodenum, JEJ: jejunum, UMB: umbilicus, IL: ileum, CC: caecal appendix, HG: hindgut.
