Genomic organization of the mouse fibroblast growth factor receptor 3 (Fgfr3) gene

The fibroblast growth factor receptor 3 (Fgfr3) protein is a tyrosine kinase receptor involved in the signal transduction of various fibroblast growth factors. Recent studies suggest its important role in normal development. In humans, mutation in Fgfr3 is responsible for growth disorders such as achondroplasia, hypoachondroplasia, and thanatophoric dysplasia. Here, we report the complete genomic organization of the mouse Fgfr3 gene. The murine gene spans approximately 15 kb and consists of 19 exons and 18 introns. One major and one minor transcription initiation site were identified. Position +1 is located 614 nucleotides upstream from the ATG initiation codon. The translation initiation and termination sites are located in exons 2 and 19, respectively. Five Sp1 sites, two AP2 sites, one Zeste site, and one Krox 24 site were observed in the 5'-flanking region. The Fgfr3 promoter appears to be contained within a CpG island and, as is common in genes having multiple Sp1-binding sites, lacks a TATA box.