The chick limb: embryology, genetics and teratology
Open Access | Review | Published: 12 February 2018
Megan G. Davey1, Matthew Towers2, Neil Vargesson3 and Cheryll Tickle*,4
1Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, UK, 2Department of Biomedical Science and the Bateson Centre, University of Sheffield, Sheffield, UK, 3School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK and 4Department of Biology and Biochemistry, University of Bath, Bath, UK
The chick embryo has a long history in investigations of vertebrate limb development because of the ease with which its limbs can be experimentally manipulated. Early studies elucidated the fundamental embryology of the limb and identified the key signalling regions that govern its development. The chick limb became a leading model for exploring the concept of positional information and understanding how patterns of differentiated cells and tissues develop in vertebrate embryos. When developmentally important molecules began to be identified, experiments in chick limbs were crucial for bridging embryology and molecular biology. The embryological mechanisms and molecular basis of limb development are largely conserved in mammals, including humans, and uncovering these molecular networks provides links to clinical genetics. We emphasise the important contributions of naturally occurring chick mutants to elucidating limb embryology and identifying novel developmentally important genes. In addition, we consider how the chick limb has been used to study mechanisms involved in teratogenesis with a focus on thalidomide. These studies on chick embryos have given insights into how limb defects can be caused by both genetic changes and chemical insults and therefore are of great medical significance.