Presence of basic fibroblast growth factor in the early Xenopus embryo

Abstract

Mesoderm-inducing activity can be extracted from Xenopus embryos, eggs or whole ovary. It binds to heparin and can be neutralized by heparin or anti-bFGF but not by anti-TGFβ. Two molecular forms can be identified by Western blotting and have molecular weights of about 19 and 14K. The content in embryos is about 7 units g-1 (approximately 7 ng ml-1) which would be sufficient for it to be acting as an endogenous inducer of ventral mesoderm. Attempts to detect TGFβ-like inducing factors in embryos were not successful.