Fig. 1. ngn1 is expressed in RB neurons and in dorsal root and cranial ganglia. (A) Dorsal view of 6-somite stage embryo, processed to reveal ngn1 RNA expression (cytoplasm, dark blue) and anti-Islet immunoreactivity (nuclear, brown). Cells expressing ngn1 but not Islet have a clear nucleus (asterisk, A'). In all figures, embryos are shown with anterior towards the left, except in transverse sections. In caudal neural plate (inset A'), RBs (white arrowheads) and a few cells adjacent to RBs (asterisk) express high levels of ngn1. By contrast, more rostrally, in developmentally older neural plate (inset A''), cells surrounding RBs do not express high levels of ngn1. (B) Lateral view of somites 5-12 of an embryo fixed at 34 hpf and processed to reveal ngn1 expression in DRGs (arrowheads). Expression is also visible in neural tube (NT). (C) Transverse section of the embryo in A showing ngn1 expression in DRGs (arrowheads) and neural tube (NT). (D) Lateral head view of 34 hpf embryo showing ngn1 expression in nascent cranial ganglia (arrowheads). Scale bars: 50 µm.
