Heterogeneous regulatory patterning of the larval ciliary bands as visualized by WMISH. (A) Schematic describes the position of the two larval ciliary bands (red) from oral (left) and lateral (right) views. A, anus; CB, ciliary band; M, mouth. (B-F) WMISH. Expression of (B and C) foxj1 and (D and E) klf13 is initially broad throughout (B and D) the ectoderm of gastrulae, then later is restricted to (C and E) the larval ciliary bands. Arrows in Figure 3B show the vegetal limits of foxj1 expression. Arrows in Figure 3D point to a clearing above the vegetal pole where transcripts of klf13 were detected. klf13 transcripts are additionally detected in an ectodermal territory near the mouth (arrows in Figure 3E). (F) foxg is first expressed within two ectodermal domains on the oral side of gastrulae. (G) FISH of nk2.1 (green) and ciliary band marker foxg (red) highlights nk2.1 expression in only the transverse preoral ciliary band. Colocalization is shown in yellow. (H-M) WMISH. foxd is expressed within a single domain in (H) the oral side ectoderm of gastrulae and (I) in the transverse, preoral larval ciliary band. gbx is expressed in one domain in (J) the oral side ectoderm in gastrulae and in (K) the transverse postoral larval ciliary band. (L) nk1 is expressed in the transverse postoral ciliary band in the larva. (M) A two-probe WMISH shows lhx2 expression in a spotted pattern in the aboral ectoderm (arrows, left) opposite of foxg expression (arrowheads, right). Embryos are oriented with the animal pole up and laterally, except in Figures 3E, 3G, 3I and 3K, which are oral views. In lateral views, the oral side is to the right.