EXPRESSION CLONING, DEVELOPMENTAL EXPRESSION AND CHROMOSOMAL LOCALIZATION OF FIBROBLAST GROWTH FACTOR-VIII

A mouse testis cDNA library in lambda pCEV27 eukaryotic expression vec tor was transfected in NIH3T3 fibroblasts and several transformed foci were identified. A plasmid with high-titered focus forming activity w as rescued from one of these transformants. Structural analysis of thi s cDNA predicted a protein identical to androgen induced growth factor (AIGF), recently identified as the eighth member of the fibroblast gr owth factor (FGF) family, A 1.6 kiIobasepair transcript of the FGF-8 g ene was detected in testis but not in other adult tissues analysed. Du ring development, expression of FGF-8 was restricted to embryonic days 9 through 13 suggesting that the growth factor plays a role during a discrete stage of mouse embryogenesis, An exon-containing genomic clon e of human FGF-8 was isolated and structural comparisons indicated tha t the gene structure of this region is highly conserved among the FGF genes. Using a panel of human-rodent somatic cell hybrids, the FGF-8 g ene was localized to human chromosome 10.