Morphogenesis is the evolutionary process leading from the few cells in an
embryo to the very complex shapes of organs or animals; how it is guided
remains an open and fascinating question. In this paper, we show that
complex patterns observed in the intestine can be understood from
simple mechanical arguments.
When cells divide in an epithelial monolayer, they exert a pressure on
their surroundings, which is at the origin of the intestinal tube
wrinkling: the monolayer buckles. By forming large wrinkles, the area of
the tube is increased. This buckling theory predicts patterns strikingly
similar to those observed in the small intestine.
The shape of a tissue also has important effects on division : shape
can feedback growth. Adding this ingredient to the model allows us to
explain the patterns observed in the large intestine as well,
providing a comprehensive physical theory of the morphogenesis of the
intestine.
Intestinal shape and renewal seem to be at least partially controlled by a
mechanical balance. This fine balance is disrupted in the case of
intestinal diseases and should be studied more carefully in the future,
as it may shed some new light on these diseases.
