Fig. 10.
Survival and generation of late-born RGCs are inhibited in rescued animals. (A–B) βIII-tubulin (TuJ1) staining of rescued (Crx>Math5 Tg; Math5 KO) retinas at E15.5 and E17, compared to Math5 heterozygous littermates (het, A,C) or Math5 wild-type (WT) control (E17.5, B). Math5 KO (left) retinas form a nerve fiber layer, but there is no clear coalescence of axons into an optic nerve. Crx>Math5 Tg rescued retinas have thin optic nerves, and these occasionally form axon knots in the optic stalk (arrowhead, inset). (C–D) Rescued and control sections stained for cleaved Caspase-3 (arrows) at E16.5 to mark apoptotic cells. Dying cells primarily reside in the forming ganglion cell layer. Crx>Math5 Tg rescued animals (Tg; KO) exhibit increased levels of apoptosis as compared to Math5 KO mice, which have much higher levels of cell death than heterozygous animals. (E) TuJ1 staining of E15.5 Crx>Math5 BAC; Math5 KO mice, shows partial rescue of optic nerve development and the appearance of a similar RGC axon knot (arrowhead). Scale bar, 50 µm.
