| |
Fig. 1. Expression of fkh5 begins at the onset of gastrulation in posterior dorsal ectoderm, and is subsequently expressed in diencephalon, midbrain, hindbrain, and spinal cord. (A) Northern analysis of fkh5. 1.25 embryo equivalents per lane were analyzed for fkh5 RNA (top row) at various embryonic stages shown. Ethidium stained 18S rRNA is the loading control (bottom row). (B) Whole-mount in situ analysis of fkh5. Embryos were analyzed by in situ hybridization and in some cases sectioned as described in Section 4. Embryo orientations are indicated by: A, anterior; P, posterior. Arrows in (a,c,e) indicate the dorsal lip of the blastopore. (a) Stage 10.5, dorsal view. (b) Stage 10.5, sagittal section, showing fkh5 expression is in non-involuted tissue only. The dotted line indicates the boundary between involuted and non-involuted tissue. (c) Stage 11.5, dorsal view. (d) Stage 11.5, sagittal section, showing fkh5 expression in the dorsal ectoderm only. (e) Stage 13, dorsal view. (f) Stage 13, sagittal section. Bracket indicates fkh5 expression. (g) Stage 19, dorsal view. Arrows in (g) indicate positions of sections in (h,i). (h,i) Coronal sections of stage 19. Brackets indicate fkh5 expression. (j) Stage 27, lateral view. (k–n) Double whole-mount in situ hybridizations (as described in Section 4). In all panels, embryos are stage 16–18 embryos, with fkh5 always in purple and opl, otx2 or en2/krox20 in blue. (k) fkh5 and otx2 double in situ, dorsal view. (l) fkh5 and otx2 double in situ, anterior view. Arrows in (k,l) indicate the overlap of fkh5 and otx2. (m) fkh5 and opl, dorsal view. (n) fkh5 and opl, anterior view. (o) fkh5 and en2/krox20 mixed probe, dorsal view. (p) fkh5 and en2/krox20 mixed probe, anterior view. Brackets in (o,p) indicate the partial overlap of fkh5 expression stripes with en2 in the midbrain. The arrowhead indicates partial overlap with the r5 stripe of krox20 expression in the midbrain. |
