Platelet-derived growth factor A chain is maternally encoded in Xenopus embryos

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Science  02 Sep 1988:
Vol. 241, Issue 4870, pp. 1223-1225
DOI: 10.1126/science.3413486


Transcription of zygotic genes does not occur in early Xenopus embryos until the mid-blastula transition, 6 to 7 hours after fertilization. Before this time, development is directed by maternal proteins and messenger RNAs stored within the egg. Two different forms of the A chain of platelet-derived growth factor (PDGF) are shown here to be encoded by maternal messenger RNAs. The two forms closely resemble human PDGF; however, the long form contains a hydrophobic region near the carboxyl terminus. The presence of PDGF messenger RNA in the embryo supports the idea that endogenous growth factors act at the earliest stages of embryogenesis.