Fig. S4

lmx1b.2 and wnt1 expression in overlapping and non-overlapping domains in the hindbrain. (A,A′) lmx1b.2 mRNA and (B,B′) wnt1mRNA in situ hybridization of 24 hpf whole mount hindbrains in dorsal view (A,B) and cross-sections (A′,B′) at the level indicated by the white dotted line in A and B. In the hindbrain, lmx1b.2 is expressed dorsally in the roof plate cells (including the membrane covering the ventricle as well as the “shoulder” region indicated by black arrow in A and A′) and ventrally in the serotonergic neurons (white arrows in A and A′). In the hindbrain, wnt1 expression overlaps with lmx1b.2 expression in the roof plate cells (black arrows in B and B′). wnt1 expression also occurs at elevated levels in the dorsal part of rhombomere boundaries, as well as at lower levels throughout the dorsal hindbrain. The cross-section in B′ indicates the elevated levels of expression of wnt1 at the boundary between r5 and r6. r4, rhombomere 4.