Fig. 5. Ash1a and Ngn1 regulate the expression of Notch ligands. Dorsal views of brains showing expression of deltaA, deltaB and deltaD in wild-type (WT), flh^–/–, and single ash1a, ngn1 or double morphants. Probes used are indicated bottom right, stage bottom left, and `genotype' at the top right of each panel. Arrowheads in B indicate two faint deltaA-positive cells. Expression of all three Delta genes was affected in the ash1a morphants (C,F,I,K,O,S), and more severely reduced or completely absent in the ash1a/ngn1-double morphants (M,Q,U). Scale bar: 10 µm.