Fig. 4. Ash1a and Ngn1 function downstream of Flh and upstream of neuroD. Dorsal views of brains with anterior at the top, showing expression of flh and neuroD in wild-type (WT), ash1a, ngn1 and ash1a/ngn1-double morphant embryos. Probe and stage are indicated on the left, `genotype' above. Expression of flh was unaffected following the impairment of either or both Ash1a and Ngn1 function (B-D). By contrast, expression of neuroD was affected by the reduction of Ash1a (F) or of both Ash1a and Ngn1 (H). Scale bar: 10 µm.