8 Embryonic Explant and Slice Preparations for Studies of Cell Migration and Axon Guidance

This chapter describes methods for preparing explants and slice preparations of the embryonic chick and mouse. In addition, it describes methods for culturing explants of embryonic mouse tissue. Each culture system possesses distinct advantages and should be adaptable to many studies of developmental processes that occur over a wide spatiotemporal range. These preparations maintain several features common to the intact embryo, including tissue structural integrity and the correct distribution of various molecular constituents for at least 2-3 days. Of critical importance, the explants and slices retain their tissue architecture for 1-3 days in culture and possess molecular characteristics typical of intact embryos. Furthermore, these types of preparations allow one to disrupt the embryonic environment through the addition of various blocking reagents and observe the subsequent effects of these manipulations via static images and using time-lapse videomicroscopy. These types of paradigms should continue to offer a rich cellular and molecular arena in which to study early developmental events, including cell migration and process outgrowth.