||FIG. 2. frzb2 and sizzled2 are expressed in tissues that can modulate A/P ectodermal patterning. (A) Northern blot analysis of FRP expression. Northern blots containing 5 mg of total RNA from a developmental series. RNA from egg (lane 1), stage 8 (2), stage 10 (3), stage 11 (4), stage 12 (5), stage 14 (6), stage 18 (7), stage 24 (8), and
stage 38 (9). Top: Blot probed with frzb2 showing two zygotic bands (arrowheads). Small arrow indicates a weak maternal transcript. Middle: Northern blot probed with sizzled2, which detects a single band (arrowhead). Bottom: Ethidium bromide staining of ribosomal
RNA (loading control). (B, C) Whole-mount in situ hybridization analysis. Embryos were cultured as described and harvested at various developmental stages for in situ hybridization analysis.
Antisense RNA probes were labeled with digoxigenin–UTP and appear in purple. (B) Expression pattern of frzb2, dorsal to the top in all images, anterior to left in d, e, and f. (a) Stage 10.5, early gastrula,vegetal view with sagittal section to the right; (b) stage 11.5 vegetal view; (c) stage 14, anterior view; (d) stage 24; (e) stage 24, compared to muscle actin (Mohun and Garrett, 1987), bottom embryo; (f) stage 32. (C) Expression pattern of sizzled2, all views ventral,
anterior to the left. (a) Stage 11.5; (b) stage 12; (c) stage 13; (d) stage 16; (e) stage 24; (f) stage 26, compared to a-globin (Kelley et al., 1994), bottom embryo. cg, cement gland; vbi, ventral blood islands; m, midbrain; o, otic vesicle. A, anterior; P, posterior; D, dorsal, V, ventral; vg, vegetal.