Fig 4

miR-1 MO-injected embryos displayed defective neural crest cells differentiation. Embryos were viewed dorsally, anterior to the top, at 24 hpf. Expression of dlx2a (A), dlx3b (B), ngn1 (C), and crestin (D) is shown. Expression of the pharyngeal homing marker gene dlx2a was reduced in the neural crest stream (S1, S2, S3) in miR-1 MO-injected embryos (A). General features of dorso-ventral patterning appeared affected as shown (arrows) by decreased expression of dlx3b (B). ngn1, a marker of neuron differentiation, was downregulated in miR-1 morphants (arrows) (C). The expression of neural crest marker crestin was reduced in the cranial region and the branchial primordia (arrows) (D). microRNA-1, miR-1; morpholino, MO. Taken together, our data suggest that miR-1 loss of function interfered with the development of normal neural crest derivatives through disruption of neural crest cell migration and differentiation.