Figure 1. The allantoic core domain houses putative precursor PGCs.
Schematic sagittal view of the embryo’s posterior region illustrating that precursor PGCs (red circles) are specified within the allantoic core domain (ACD; royal blue), which incorporates the primitive streak/epiblast. The inset shows an illustration of an entire embryo (~E7.25) to give context to the location of the mesodermal bulge that houses the ACD; the boxed area corresponds to magnified view. al, allantois; am, amnion; Epi, epiblast; ExE, extraembryonic endoderm; VE, visceral endoderm; D, dorsal; V, ventral; A, anterior; P, posterior.