Progress in science appears part and parcel with the introduction of new experimental methods. Three landmarks in the history of experimental embryology emerged from new methods. The first was von Baer's1 experiments showing how the chick embryo develops from a more general to a specific, detailed body design. The second was Spemann's2 microsurgical experiments on embryonic tissues showing the effects of one tissue upon another leading to differentiation of a third, and hypothetical chemical organizers of embryonic development. The third was in situ hybridization (Pardue et al., 1970)3 modified and improved by Harland4 for localization of bone morphogenetic protein (BMP) including BMP receptors.5–10 BMP is a hydrophobic low molecular weight polypeptide42 that evolved in species in the fossil record 500 million years ago. It is distinguished by heterotopic bone development in response to implants of nanogram quantities with a carrier in muscle. In this issue of JBMR, Nifuji et al.11 present circumstantial evidence of BMP‐2– and ‐4–induced skeletal system development. The evidence is based on whole mounts of chick embryos and in situ hybridization, using digoxigenin‐labeled mRNA probes to localize endogenous BMP‐2 and BMP‐4. Exogenous BMP (rhBMP‐2) was implanted in pellets of glass in dorsal mesoderm. Transcripts for BMP‐4 ligand and its receptors were expressed in dorsal ectoderm and mesoderm. The implants of exogenous BMP‐4 and BMP‐2 produced anomalies of vertebra, ribs, and scapulae.
Copyright remains with the authors and publisher.
Progress in science appears part and parcel with the introduction of new experimental methods. Three landmarks in the history of experimental embryology emerged from new methods. The first was von Baer's1 experiments showing how the chick embryo develops from a more general to a specific, detailed body design. The second was Spemann's2 microsurgical experiments on embryonic tissues showing the effects of one tissue upon another leading to differentiation of a third, and hypothetical chemical organizers of embryonic development. The third was in situ hybridization (Pardue et al., 1970)3 modified and improved by Harland4 for localization of bone morphogenetic protein (BMP) including BMP receptors.5–10 BMP is a hydrophobic low molecular weight polypeptide42 that evolved in species in the fossil record 500 million years ago. It is distinguished by heterotopic bone development in response to implants of nanogram quantities with a carrier in muscle. In this issue of JBMR, Nifuji et al.11 present circumstantial evidence of BMP‐2– and ‐4–induced skeletal system development. The evidence is based on whole mounts of chick embryos and in situ hybridization, using digoxigenin‐labeled mRNA probes to localize endogenous BMP‐2 and BMP‐4. Exogenous BMP (rhBMP‐2) was implanted in pellets of glass in dorsal mesoderm. Transcripts for BMP‐4 ligand and its receptors were expressed in dorsal ectoderm and mesoderm. The implants of exogenous BMP‐4 and BMP‐2 produced anomalies of vertebra, ribs, and scapulae.
Copyright remains with the authors and publisher.