Axes and Germ Layers Setting up the body axes. The origin and specification of the germ layers. The Mesoderm and Early Nervous System Somite formation and patterning. The role of the organizer region and neural induction. Polarization of the body axes during oogenesis.
Zygotic genes pattern the early embryo.
Segment polarity genes and compartments. Cellular slime molds. Cleavage and formation of the blastula. Neural tube formation. The reversibility and inheritance of patterns of gene activity.