EARLY REGIONALIZED EXPRESSION OF A NOVEL XENOPUS FIBROBLAST GROWTH-FACTOR RECEPTOR IN NEUROEPITHELIUM

A cDNA encoding a novel Xenopus fibroblast growth factor receptor, XFG FR4B, has been cloned. XFGFR4B mRNA is detected throughout embryogenes is. However, from the late gastrula stage on, XFGFR4B transcripts are expressed in two defined areas of the anterior neural plate. interesti ngly, these two regions are fated to become parts of the retina, midbr ain, hindbrain, and otic vesicle, all of which continue to express XFG FR4B mRNA in tailbud stage embryos and early tadpoles. Expression of X FGFR4B mRNA can be maintained at neurula stage in isolated blastula ec toderm in response to mesodermal induction by activin or neural induct ion by noggin, suggesting that XFGFR4B expression might be regulated b y early cell interactions. Distribution of XFGFR4B mRNA suggests that XFGFR4B might serve an important function during patterning of neuroep ithelium. (C) 1996 Academic Press, Inc.