Well-defined growth factors promote cardiac development in axolotl mesodermal explants.
The effect of growth factors on the formation of cardiac mesoderm in the urodele, Ambystoma mexicanum (axolotl), has been examined using an in vitro explant system. It has previously been shown that cardiac mesoderm is induced by pharyngeal endoderm during neurula stages in urodeles. In this study, explants of prospective cardiac mesoderm from early neurula stage embryos rarely formed beating cardiac tissue in culture. When transforming growth factor beta-1 (TGF-beta 1) or platelet-derived growth factor BB (PDGF) was added to such explants, the frequency of heart tissue formation increased markedly. The addition of other growth factors to these explants did not enhance cardiac mesoderm formation. The addition of basic fibroblast growth factor (bFGF) to prospective heart mesoderm derived from later stage embryos resulted in a decreased tendency to form cardiac tissue. These results suggest that growth factors analogous to TGF-beta 1, PDGF, and bFGF may regulate the initial stages of vertebrate cardiac development in vivo.
Howard Hughes Medical Institute, University of California, San Francisco 94143-0724.
A J
AJ
Muslin
L T
LT
Williams
D000557:Ambystoma; D000818:Animals; D046508:Culture Techniques; D004627:Embryonic Induction / Q000187:drug effects*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000196:embryology*; D008648:Mesoderm / Q000187:drug effects / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2