| |
Fig. 3. Whole mount in situ hybridization (BMP-2) of Xenopus embryos. Xenopus albino embryos were hybridized with a digoxygenin labelled BMP- 2 antisense RNA derived from a 737 bp Sac IlPst I fragment and processed as described in Section 4. (A) From left to right: four-cell (st. 4), 32-cell (St. 6). morula (St. 7), blastula (St. 8.5) and gastrula (st. 11.5) stage embryos. Asterisk denotes the blastoporus. (B) Late neurula (St. 19) (dorsal view). (C) St. 21 (dorsal view). (D) Transverse section (30µm) through stage 17 embryo. The arrowhead points at staining in the dorsal midline. (E) St. 22/23 embryos. Arrowheads denote staining in the dorsal midline (upper) and in anterior and posterior mesoderm (lower). (F) Transversal section (100�m) (trunk region) through a St. 24 embryo. (G) St. 24, anterior view. Arrows denote intense staining at two frontal loci. (H) St. 28 embryo. The arrow points at the olfactory placode. (I) St. 28 embryos, frontal view. Note staining of the pineal body and of the olfactory placodes. (J) Parasagittal section through st. 28 embryo. (K) Anterior transversal section (100µm) according to the arrow in (I) through st. 30 embryo. (L) Higher magnification of an anterior transversal section (30µm) showing the mushroom-shaped pineal body and its communication to the third ventricel (arrowhead). (M) St. 32 embryo. (N) Magnification of the tailbud regions of St. 29 (top) and st. 33 (bottom) embryos. The arrows point at the disintegration of neural crest cells. cg: cement gland; e: eye anlage; h: heart anlage; nc: neural crest; no: notochord; nt: neural tube; o: olfactory placode; p: pineal body. |
