The results presented here confirm previous observations that bFGF stimulates PGC growth in culture. This effect is apparent in the absence of a preformed feeder layer or with purified PGCs plated on a feeder layer. Basic FGF stimulates PGC growth on a variety of feeder layers including bone marrow-derived stromal cells (Sl220), primary mouse fibroblasts, and the established mouse fibroblast cell lines STO, NIH3T3, and 10T1/2 cells (unpublished results). The ability of bFGF to stimulate PgC growth independently of the feeder cell type suggests that it may exert its action, in part, directly on the PGCs. birth control yasmin
The demonstration that 125I-bFGF can bind to PGCs shows that PGCs have a cell surface FGF receptor. RNase protection analyses indicate that FGFR-1 and FGFR-2 are expressed in the 11.5 dpc urogenital ridge. Single primer pair RT-PCR analysis suggests that FGFR transcripts are encoded in the RNA of highly purified 11.5 dpc PGCs. While it is possible that bFGF can promote PGC growth indirectly through both the STO feeder cells and the somatic cells of the urogenital ridge, our data indicate that PGCs can bind and respond to bFGF. Together, these results are most consistent with a model in which bFGF acts directly on PGCs.