| |
Fig. 5. Anterior neural ectoderm is necessary to induce mesodermal Nkx2.5 expression. (A) Transcripts encoding truncated BMP receptor were injected and AC explants (n = 36) were isolated and grown to stage 15. Half of the explants were used to extract RNA for RT-PCR analysis (upper) and the other half to extract proteins for Western analysis (lower). (B) Animal caps were removed at stages 8–9 from whole embryos. “Mildly affected” embryos were allowed to grow to stage 15, and whole embryos were extracted and subjected to RT-PCR analysis of their RNA (upper) or to in situ hybridization with probes to Nkx2.5, MyoD, OTX2 and Krox20 (lower). (C) DMZ and VMZ explants were dissected at stage 10.25. Ectoderm was removed from some of the DMZ explants and was recombined with VMZ explants (pairs of VMZ: dorsal ectoderm) or grown alone (ecto.). At stage 15, total RNA was extracted and RT-PCR analysis was performed. (D) Several embryos were injected with mRNA encoding FGF8, and animal caps were removed at stages 8–9. Embryos were allowed to grow to stage 15 and in situ hybridization with probes to Nkx2.5 and MyoD was performed. |
