FGF-8c, carrier-free

FGF-8 is a member of the fibroblast growth factor family that was originally discovered as an androgen-induced growth factor essential for the androgen-dependent growth of mouse mammary carcinoma cells. The mouse FGF-8 primary transcript isalternatively spliced to generate at least 8 secreted isoforms that differ only at their amino terminis. The FGF-8 isoforms differentially activate the various alternatively spliced forms of fibroblast growth factor receptors 1 - 3, and fibroblast growth factor receptor 4. FGF-8b has been shown to activate the ‘c’ splice form of FGF R2, FGF R3, and FGF R4. During mouse development, expression of FGF-8 was restricted to embryonic days 9 through 13. The pattern of FGF-8 expression during mouse development suggests a role for FGF-8 in multiple regions of ectodermal differentiation in the post-gastrulation mouse embryo. These include a role in outgrowth and patterning of the face, limbs, and central nervous system of the vertebrate. The FGF-8 locus has been mapped to mouse chromosome 19 and human chromosome 10. The human FGF-8 gene has recently been cloned and shown to encode only 4 potential isoforms. Mouse and human FGF-8a and FGF-8b isoforms are 100% identical and FGF-8e and FGF-8f isoforms are 98% identical at the protein sequence level. However, human proteins corresponding to the mouse FGF-8c, d, g and h isoforms do not exist (MacArthur, C.A.  et al., 1995, Development 121:3603 - 3613; Crossley, P.H. et al., 1996, Cell 84 :127 - 136; Gemel, J. et al., 1996, Genomics 35:253 - 257).