Fig. 1.

Pax2 is required for otic marker expression. Control (A, A′, C, C′, E, E′) or Pax2 MOs (B, B′, D, D′, F, F′, H H′) were electroporated into otic precursors at the 1–2 somite stage. At HH10–12, Eya1 (A–B′, a–b′) and Gata3 (C–D′, c–d′) expression is present in cells carrying control MOs (green in A, a, C, c; arrow heads), but absent in Pax2 MO electroporated cells (green in B, b, D, d; arrow heads). Note in d′: non-invaginated placode on targeted side. Pax2 protein expression is not affected by control MOs (E, E′, e, e′; arrow head), but absent in cells with Pax2 MOs (F, F′, f, f′; arrow head). Note the difference in cell shape of the control and Pax2 MO cells in e (white arrow head) and f (open arrow head). Loss of Pax2 does not affect Sox2 expression in the otic placode (H, H′, h′). Gata3 expression is rescued when otic cells are co-electroporated with splice blocking MOs and a Pax2 expression construct (G, G′, g, g′). Lines in A′–D′, E, F, G′ and H′ indicate the level of sections shown in a–g, a′–g′.