Role of FGF3 in otic capsule chondrogenesis in vitro: an antisense oligonucleotide approach

Initiation of otic capsule chondrogenesis depends on interactions between the otocyst and surrounding periotic mesenchyme. We previously reported localization of endogenous basic fibroblast growth factor (FGF2) to the epithelium of the mouse otocyst, and initiation of chondrogenesis in cultured periotic mesenchyme by this epithelial-derived signaling molecule. We now report that FGF3, related to FGF2, can also initiate otic capsule chondrogenesis. We show localization of endogenous FGF3 to the otocyst, and suppression of chondrogenesis by antisense oligonucleotides complementary to different regions of the murine FGF3 gene. Our results support a role for FGF3 in otic capsule formation in situ.