Fig. 1

Whole-mount in situ analysis of hsp27 mRNA expression before and after heat shock. All embryos shown were hybridized with the hsp27 antisense riboprobe. (A–K) Control untreated embryos. (A′–K′) Embryos treated with heat shock at 37 °C for 1 h prior to fixation for in situ hybridization and the stages are indicated for the time fixation. (A,A′) 4 hpf embryo. (B,B′) 6 hpf embryo. (C, C′) Enlarged view of cross section of embryos shown in (B, B′). Nuclei stained with DAPI. Arrows indicate the outermost enveloping layer (en). (D,D′) Enlarged view of cross section of embryo at the blastoderm margin shown as boxed region in (B, B′) after DAPI staining. Arrows indicate the involuting cells in the margin. (E,E′,F,F′) Lateral (E, E′) and enlarged view of tail (F, F′) of 26 hpf embryos. G,G′: Lateral view of a 48 hpf embryos. (H,H′,I,I′,O,P) 72 hpf embryos; Lateral whole-mount view (H, H′), lateral view of head region (I, I′) and cross section of (I′) at the levels indicated. (J,J′,K,K′,L–N,Q,R) 96 hpf embryos: Lateral whole-mount view (J, J′), lateral view of head region (K, K′), dorsal view of the embryo in (J′) at different optical levels (L) and ventral view (M) of dissected embryo in (J′). (N) Eye of embryo shown in (J′). (Q,R) Cross sections of embryo shown in (K′) at the levels indicated. Abbreviation: am, abdominal muscles; ea; ear; en, enveloping layer; ep, epiphysis; ey, eye; fp, floor plate; h, heart; le, lens epithelium; mhb, midbrain hindbrain boundary; nc, notochord; olf, olfactory pits; pm, pharyngeal muscle; psm, presomitic mesoderm; som, somite; te, tectum; tg, tegmentum; y, yolk. Scale bar: 100 μm.