Genomic structure, mapping, activity and expression of fibroblast growth factor 17

Fibroblast growth factors are essential molecules for development. Here we characterize Fgf17 a new member of the fibroblast growth factor (FGF) famil y. The Fgf17 gene maps to mouse chromosome 14 and is highly conserved betwe en mouse and human (93% identity). It exhibits 60% amino acid identity with Fgf8 and 50% identity with Fgf18. Both Fgf8 and Fgf17 have a similar struc ture and a similar pattern of alternative splicing in the 5' coding region. When expressed in 3T3 fibroblasts, mouse FGF17 is transforming, indicating that it can activate the 'c' splice form of either FGF receptor (FGFR) one or two. During midgestation embryogenesis, in situ hybridization analysis localized Fgf17 expression to specific sites in the midline structures of t he forebrain, the midbrain-hindbrain junction, the developing skeleton and in developing arteries. Comparison to Fgf8 revealed a striking similarity i n expression patterns, especially in the central nervous system (CNS), sugg esting that both genes may be important for CNS development, although Fgf17 is expressed somewhat later than Fgf8. In the developing skeleton, both ge nes are expressed in costal cartilage while Fgf8 is preferentially expresse d in long bones. In the developing great vessels Fgf17 is preferentially ex pressed, suggesting that it may have a more prominent role in vascular grow th. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.