DIFFERENTIAL EXPRESSION PATTERNS OF MESSENGER-RNAS FOR MEMBERS OF THEFIBROBLAST GROWTH-FACTOR RECEPTOR FAMILY, FGFR-1-FGFR-4, IN RAT-BRAIN

We have examined the region-specific expression of mRNAs for four memb ers of rat FGF receptor family, FGFR-1, FGFR-2 FGFR3, and FGFR-4, in r at brain by in situ hybridization. The FGFR-1, FGFR-2, and FGFR-3 mRNA s were expressed widely but differentially in the brain. However, the FGFR-4 mRNA was not expressed in the brain. The FGFR-1 mRNA was strong ly expressed in several regions including the hippocampus, cerebellum, and pedunculopotine tegmental nucleus. The FGFR-2 mRNA expression was high in the choroid plexus, and moderate in the fiber-rich regions (t he corpus callosum, external capsule, and internal capsule) and the ol factory bulb. The FGFR-3 mRNA was expressed diffusely in the brain. We have also examined the cellular localization of these mRNAs in the br ain. Although the FGFR-1 mRNA was expressed preferentially in neurons, the FGFR-2 and FGFR-3 mRNAs were expressed preferentially in glial ce lls. The present findings that the FGFR-1, FGFR-2, and FGFR-3 mRNAs we re expressed widely but with region- and cell-specificity in the brain indicate that these receptors have different roles in the brain. (C) 1994 Wiley-Liss, Inc.