Expression of transforming growth factor-beta 3 by embryonal carcinoma cells, parietal endoderm-like cells and early mouse embryos.

Utilizing the technique of reverse transcription-polymerase chain reaction (RT-PCR), we have examined the expression of transforming growth factor-beta 3 (TGF-beta 3) by embryonal carcinoma (EC) cells, EC-derived differentiated cells and early mammalian embryos. Using a TGF-beta bioassay, we determined that PYS-2 cells express considerable TGF-beta activity that cannot be completely neutralized by antibodies specific for TGF-beta 1 and TGF-beta 2. We also have determined that PYS-2 cells, as well as F9 EC cells and their differentiated cells, express transcripts for TGF-beta 3. In addition, we have determined that blastocysts, cultured for three days in serum-containing medium, express TGF-beta 3 transcripts. Thus, our data suggest that expression of TGF-beta 3 is initiated during early stages of mammalian development.