Int. J. Dev. Biol. 62: 109 - 119 (2018)

https://doi.org/10.1387/ijdb.170325ct

Vol 62, Issue 1-2-3

Special Issue: The Chick Embryo Model System

Chick midgut morphogenesis

Published: 14 March 2018

Tyler R. Huycke and Clifford J. Tabin*

Department of Genetics, Harvard Medical School, Boston, MA, USA

Abstract

The gastrointestinal tract is an essential system of organs required for nutrient absorption. As a simple tube early in development, the primitive gut is patterned along its anterior-posterior axis into discrete compartments with unique morphologies relevant to their functions in the digestive process. These morphologies are acquired gradually through development as the gut is patterned by tissue interactions, both molecular and mechanical in nature, involving all three germ layers. With a focus on midgut morphogenesis, we review work in the chick embryo demonstrating how these molecular signals and mechanical forces sculpt the developing gut tube into its mature form. In particular, we highlight two mechanisms by which the midgut increases its absorptive surface area: looping and villification. Additionally, we review the differentiation and patterning of the intestinal mesoderm into the layers of smooth muscle that mechanically drive peristalsis and the villification process itself. Where relevant, we discuss the mechanisms of chick midgut morphogenesis in the context of experimental data from other model systems.

Keywords

intestine morphogenesis, gut looping, villus formation, smooth muscle, biomechanics