Abstract

The pattern in which intestines are folded within the body cavity is conserved between individuals and characteristic of species. This reproducible form and structure is governed by simple mechanics related to the way the body grows during embryogenesis. Throughout development the gut tube, anchored to a muscular sheet called the mesentery, grows faster than the body surrounding it, forcing it to loop. We used developmental and biophysical experiments (mathematical theory and both computational and physical models) to determine what drives the characteristic looping, focusing on the chick gut. We demonstrated that pattern in which the gut loops is determined solely by the tissue-scale elasticity, geometry and relative rates of growth of the mesentery and gut. This model accounts for variation in gut patterns, during development and in a range of species including quail, finch and mouse.