INVOLVEMENT OF ANDROGEN-INDUCED GROWTH-FACTOR (FGF-8) GENE IN MOUSE EMBRYOGENESIS AND MORPHOGENESIS

Androgen-induced growth factor (AIGF/FGF-8) has purified from a mouse mammary carcinoma cell line and its cDNA cloning revealed that AIGF is the eighth member of the fibroblast growth factor family. To clarify a biological role of FGF-8, Northern blot analysis of various adult ti ssues was carried out, but no expression was found. However, whole mou nt in situ hybridization of 7.5- to 14.5-day gestation (E7.5-14.5) emb ryos revealed six predominant expression domains: [1]primitive streak region (E7.5-9.75); [2]midbrain-hindbrain border (E8.0-10.5); [3]rostr al forebrain (E8.0-10.5); [4]limb ectoderm and apical ectodermal ridge (E9.25-13.5); [5]nasal placode and epithelium (E9.5-12.5); and [6]bra nchial arch ectoderm (E8.5-11.5). The embryonic expression pattern sug gests a unique role of FGF-8 in mouse development, especially in gastr ulation, brain development, and limb and facial morphogenesis. (C) 199 4 Academic Press, Inc.