Using a PCR-based cloning strategy we have isolated a cDNA from mouse brain and named it fex, because it codes for a novel putative G protein-coupled receptor expressed in follicles. The deduced amino acid sequence shows a higher degree of homology to the family of glycoprotein receptors, namely those for FSH, LH, and TSH, than to other G protein-coupled receptors. With 18 leucine-rich repeats FEX exhibits features in its N-terminal portion characterizing it as unique within the glycoprotein receptor family. In the adult mouse fex expression was detected in the male and female gonads, the adrenal medulla, and the olfactory bulb of the brain. During embryonic development fex transcripts were detected transiently in various tissues, particularly in selected regions of the central nervous system, the developing face, the intervertebral discs anlagen, and the limb buds. Because fex was expressed during periods of active morphogenesis, it may be an important receptor for signals controlling growth and differentiation of specific embryonic tissues.
