Km. Downs et T. Davies, STAGING OF GASTRULATING MOUSE EMBRYOS BY MORPHOLOGICAL LANDMARKS IN THE DISSECTING MICROSCOPE, Development, 118(4), 1993, pp. 1255-1266
We describe and illustrate a set of morphological landmarks for classi
fying mouse embryos by gross morphology from before gastrulation to th
e beginning of organogenesis. These landmarks are visible at the resol
ution of the dissecting microscope in embryos that are intact except f
or reflexion of Reichert's membrane. Adoption of these criteria should
facilitate interpretation of both the expression patterns of genes an
d the consequences of experimental manipulation of embryos during earl
y postimplantation development.