Fig. 13
From: New insights into mesoderm and endoderm development, and the nature of the onychophoran blastopore
Schematic overview, expression of endoderm- and mesoderm-patterning genes The early expression of marker genes is shown in gene-specific colours. In the schematic drawings of embryos, anterior is pointing upwards, ventral views. Abbreviations: a, anus; dee, dorsal extraembryonic tissue; hl, somite of the head lobe segment; j, somite of the jaw-bearing segment; L, somite of a leg-bearing segment; m, mouth; m-a, mouth-anus furrow (the embryonic slit); pp, posterior pit (blastopore); saz, segment addition zone; sp, somite of the slime papilla-bearing segment; vee, ventral extraembryonic tissue