Fig. 7

Loss of ptc1 leads to colobomas and ventral optic cup defects. 1.3 ng injection of a translation blocking morpholino targeting ptc1 transcripts (ptc1MO) results in colobomas. Lateral views of a (A) Control morpholino (ControlMO) injected and (B) ptc1 morphant at 2.5 dpf. Morphants possess bilateral colobomas (arrow in panel B). Morphants are more severely affected than blw mutants, showing medial displacement and lateral flexure of the eyes, and lens displacement. Overt brain and muscle defects are also observed. (C–E) Transverse histological sections from a 5 dpf wild-type (C) and ptc1 morphants (D, E). Severe colobomas are obvious in the morphants (arrows in panels D, E), and in the many of them the lens is also displaced and lies out of the plane of the section. pax2a expression is expanded into the retina at 24 hpf (F, G) and pax6 expression is contracted (H, I). The Hh target genes ptc1 (J, K) and ptc2 (L, M) also show expanded domains of expression in ptc1 morphants.