Regulation of gut peristalsis during development

概要

The digestive system is crucial for food digestion and absorption of nutrition in
adults. During feeding, food is transported aborally from the mouth through the
esophagus to the stomach, small and large intestines, and each region of the gut exhibits
proper movements for their functions. Peristaltic movements in the intestine, recognized
as a wavelike propagation of local contraction, is essential for bolus transportation in a
spatio-temporally regulated manner. Many gut-related disorders including irritable bowel
syndrome and postoperative paralytic ileus are accompanied by peristaltic dysfunctions,
resulting in severe digestive problems. Thus, it is important to elucidate the cellular
mechanisms by which the gut peristalsis is sustained and regulated.
Recently, it is reported that peristaltic movements are also present in the
embryonic gut of several vertebrate species including chickens, even though embryos do
not require food intake. Although the physiology of the peristalsis is well studied in the
adult body, it remains unexplored how the peristalsis is established during embryogenesis.
The embryonic chicken gut serves as an excellent model system, because gut-constituting
cells and tissues are easily manipulable experimentally and cells that constitute the
chicken gut parallel those of mammals. Chevalier and co-workers reported pioneering
studies using chicken embryonic guts, in which they described changes in speed and
frequencies of local peristaltic waves during development. These studies focused on the
timing of local peristalsis, and the data were acquired using fragments of specific gut
regions at specific times. However, the gut is a long organ, where peristalsis occurs widely
in a complex manner along the gut axis. Therefore, the spatial information of the
peristaltic patterns along the entire gut axis is necessary for understanding the regulation
of peristalsis, but such information has been lacking. ...