dlx3 and dlx7 affect otic placode formation before the onset of pax2.1 otic expression but after that of pax8. Wholemount RNA in situ hybridization at 3 somites with (A,F) wild-type, (B,G) dlx7 MO, (C,H) dlx3 MO, (D,I) dlx3+7 MO and (E,J) b380 mutant embryos. (A-E) pax8 is expressed in the presumptive otic primordia (ot) and the pronephros (pn) at this stage. Expression of this gene is unaffected by a loss of dlx3 or dlx7 function. (F-J) pax2.1 is expressed in the presumptive otic primordia (ot), pronephros (pn), midbrainhindbrain boundary (mhb) and optic stalk (not shown) at this stage. Expression is reduced specifically in the otic primordia of (H) dlx3 MOinjected embryos, and is undetectable in (I) embryos injected with dlx3+7 MO and in (J) b380 mutants. All panels show dorsal views with anterior towards the left. Scale bar: 100 µm.
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