Watching development: an easy ex ovo culturing method to directly observe late‐staged chicken embryos

Abstract

The ability to view an embryo in vivo during development is important for the teaching of developmental biology. Viewing vertebrate embryos that are protected by a shell presents a challenge. Researchers have developed techniques to grow chicken embryos outside of their shell yet this method has typically focused on the study of relatively young embryos. We have optimized the ex ovo culturing method so that embryos can be maintained for the majority of embryonic development (until at least stage HH41), enabling students to directly observe many of the aspects of development over time (e.g. limb development, eye development, etc). This technique is suitable for introductory and advanced developmental biology, embryology and anatomy classes. For advanced classes, this culturing technique enables access to late stage embryos in order to perform manipulations. An example of a manipulation that can be performed on shell‐less embryos is the implantation of beads with inhibitors in order to gain further understanding of the molecular pathways involved in the development of anatomical structures. After any manipulation, the chamber can be sealed and the embryo can be cultured further. This method enables the direct observation of normal development and manipulated development.