Fig. 6. ABp development. (A) apx-1 mutant embryo showing the lack of body morphogenesis and the massive pharynx (outlined by arrows) caused by the hyperinduction of both ABa and ABp descendants to become mesodermal cells. (B) apx-1;tbx-37 tbx-38 embryo with a small, half-pharynx (small arrows), a tail, a rectum (large arrow) and a tail spike (inset). (C,D) Ventral views of wild-type and apx-1; tbx-37 tbx-38 embryos at the onset of morphogenesis showing ventral hypodermal cells (white arrows) and the nascent rectum (black arrow). Scale bar: 5 µm.