SBU2 mutants are not neurogenic. Whole mount RNA in situ hybridization of neural markers in wild-type and SBU2 mutants. (A-J) Dorsal views; (A-H) anterior to the top, (I, J) flat mounted, anterior to the right. I’, J’ are lateral views of I and J, anterior to the top right. Morphology of the MHB domain expressing pax2a at early somitogenesis (B) indicates a delay in development of MHB in SBU2 mutants. Later, at 10 somite stage (D) pax2a expression resembles much earlier stage wild type expression domain (A). Likewise, although hindbrain marker krox20 expression is also delayed and relatively reduced (E and F) later in the development, expression pattern appears similar to wild-type embryos (G and H). RNA in situ hybridization using huC probe revealed that SBU2 embryos have reductions in early differentiating neurons (I, I’ and J, J’). Arrows denote MHB and arrowheads denote otic placode.