Fig. 3. Expression of scratch genes during early neurogenesis. Images are dorsal view with anterior to the left for all panels. (A-C) 36 hpf, (D-I) 24 hpf. (A, B) Expression of scrt1a partially overlapped with that of scrt1b (A) and scrt2 (B) in the CNS at 36 hpf. (C) Expression of scrt1b overlapped predominantly with that of scrt2 at 36 hpf. (D-F) scrt1a- (D), scrt1b- (E), and scrt2-expressing cells (F) partially overlapped with ngn1- positive neuronal precursor cells at 24 hpf. (G-I) scrt1a- (G), scrt1b- (H), and scrt2-expressing cells (I) are all huC-positive, differentiating neurons in the CNS at 24 hpf. Abbreviations: f, forebrain; h, hindbrain; m, midbrain; ret, retina. Scale bars = 100 μm.