Distinct developmental expression of a new avian fibroblast growth factor receptor.
We have cloned a new member of the fibroblast growth factor receptor family from avian embryonic RNA. The FREK (for fibroblast growth factor receptor-like embryonic kinase) primary transcript can be alternatively spliced in a tissue- and stage-specific manner to give rise to molecules containing either two or three Ig-like domains. During elongating primitive streak stages, FREK is expressed in the rostral and lateral epiblast and in the Hensen's node. From 2.5 days of development (E 2.5) on, it is expressed in various ectoderm- and mesoderm-derived structures. Most striking is FREK expression in the skeletal muscle lineage. It is highly expressed in the early myotome and, at later stages, in all skeletal muscles of the embryo. From E9 to hatching, FREK expression in the muscles decreases dramatically but is maintained in satellite cells of adult muscles. FREK transcript is elevated upon addition of basic fibroblast growth factor to serum-starved satellite cells. From this study, we conclude: (1) that the structure and pattern of expression of FREK set it apart from other cloned fibroblast growth factor receptors (FGFR) and suggest that FREK is a new member of that family; (2) that FREK may play multiple roles in early avian development, including a specialized role in the early differentiation of skeletal muscle.
Marcelle
C
C
Institut d'Embryologie Cellulaire et Moléculaire, Collège de France, CNRS, Nogent Sur Marne.
Eichmann
A
A
Halevy
O
O
Bréant
C
C
Le Douarin
N M
NM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002642:Chick Embryo; D003001:Cloning, Molecular; D003370:Coturnix; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005775:Gastrula / Q000502:physiology*; D015870:Gene Expression; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009132:Muscles / Q000196:embryology*; D016133:Polymerase Chain Reaction; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D051499:Receptor, Fibroblast Growth Factor, Type 4; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics*
D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; C086864:FGFR4 protein, Coturnix coturnix; D020794:Receptor Protein-Tyrosine Kinases; D051499:Receptor, Fibroblast Growth Factor, Type 4