Lineage allocation during early embryogenesis. Mapping of the neural primordia and application to the analysis of mouse mutants.

The methods outlined in this chapter discuss a range of techniques that have been employed for lineage analysis studies of the neural primordia from the onset of gastrulation and during neurulation. As the mouse has been extensively mapped, lineage analysis during normal morphogenesis is well understood. Attention is now focused on the tissue interactions that are essential for gastrulation and neurulation to proceed normally. The key to understanding these tissue interactions lies in the study of mutant embryos where abnormal development of specific tissue types affects the processes of gastrulation and neurulation. Lineage analysis and tissue potency experiments on particular mutant embryos will provide insight into these essential tissue interactions. As the first step toward undertaking such analysis of the neural derivatives, we have outlined the mutant strains available and detailed a protocol for the introgression of the lacZ transgene onto the mutant background.