Dissecting and Culturing Animal Cap Explants

The animal cap explant is a simple but adaptable tool available to developmental biologists. The use of animal cap explants in demonstrating the presence of mesoderm-inducting activity in the Xenopus embryo vegetal pole is one of many elegant examples of their worth. Animal caps respond to a range of growth factors (e.g., Wnts, FGF, TGF-β), making them especially useful for studying signal transduction pathways and gene regulatory networks. Explants are also suitable for examining cell behavior and have provided key insights into the molecular mechanisms controlling vertebrate morphogenesis. In this protocol, we outline two methods to isolate animal cap explants from Xenopus laevis, both of which can be applied easily to Xenopus tropicalis The first method is a standard manual method that can be used in any laboratory equipped with a standard dissecting microscope. For labs planning on dissecting large numbers of explants on a regular basis, a second, high throughput method is described that uses a specialized microcautery surgical instrument.