Fig. 10. Model of interactions between vox, vent and other genes that pattern the dorsoventral axis. (A) In the late blastula boz represses vox, vent and bmp2b in parallel. vox and vent act redundantly to repress chd, gsc and other genes expressed in dorsal mesendoderm. (B) During gastrulation, bmp2b activates expression of ventral genes, such as gata2, bmp4 and bmp2b itself, and represses expression of neural genes in ventral ectoderm. By mid-gastrulation, vox/vent and bmp2b establish a positive feedback loop in which bmp2b activates expression of vox and vent, and vox and vent activate expression of bmp2b indirectly, via repression of chd.
