Rediscovering the chick embryo as a model to study retinal development

Abstract

The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and experimental manipulation are just some of the characteristics that have made it a vertebrate model of choice for more than two millennia. Until a few years ago, the inability to perform genetic manipulations constituted a major drawback of this system. However, the completion of the chicken genome project and the development of techniques to manipulate gene expression have allowed this classic animal model to enter the molecular age. Such techniques, combined with the embryological manipulations that this system is well known for, provide a unique toolkit to study the genetic basis of neural development. A major advantage of these approaches is that they permit targeted gene misexpression with extremely high spatiotemporal resolution and over a large range of developmental stages, allowing functional analysis at a level, speed and ease that is difficult to achieve in other systems. This article provides a general overview of the chick as a developmental model focusing more specifically on its application to the study of eye development. Special emphasis is given to the state of the art of the techniques that have made gene gain- and loss-of-function studies in this model a reality. In addition, we discuss some methodological considerations derived from our own experience that we believe will be beneficial to researchers working with this system.

Characterization of Three-Dimensional Retinal Tissue Derived from Human Embryonic Stem Cells in Adherent Monolayer Cultures

“…In the absence of the optic nerve, these axons traversed the tissue and traveled along the apical side. NF200 appears only in postnatal RGCs in the developing mammalian retina [116,117], although other markers in our hESC-derived retinal tissue approximately matched the developmental stage to 6-10-week-old human fetal retina or embryonic days 14-15 stage in mouse retinogenesis [46,58,118]. These data support our conclusion that not all markers follow precisely their expression time course during retinogenesis.…”

Efficient Gene Transfer into Chicken Gonads by Combining Transposons with Polyethylenimine

“…The chick embryo, as a model system, has many applications in developmental biology research (Rashidi & Sottile, 2009;Vergara & Canto-Soler, 2012) and as a bioreactor for pharmaceutical proteins (Lillico et al, 2005). This model becomes increasingly popular because of peculiar advantages, such as a short incubation period, the accessibility of embryos, and the availability of experimental embryology (Stern, 2005).…”

Cracking the Egg: Potential of the Developing Chicken as a Model System for Nonclinical Safety Studies of Pharmaceuticals

“…The chicken embryo is an established model for the study of retinal development (Vergara and Canto-Soler, 2012). The chicken has large eyes during development and at birth, and retinal cells can be cultured in vitro (Daston et al, 1991).…”