Characterization and expression pattern of the frizzled gene Fzd9, the mouse homolog of FZD9 which is deleted in Williams-Beuren syndrome.
The frizzled gene family is conserved from insects to mammals and codes for putative Wnt receptors that share a cysteine-rich extracellular domain and seven transmembrane domains. We previously identified a novel frizzled gene, FZD3, now renamed FZD9, in the Williams-Beuren syndrome (WBS) deletion region at chromosomal band 7q11.23 and showed that its product can interact with the Drosophila wingless protein. Here, we report the characterization of the mouse homolog Fzd9. The Fzd9 gene produces a 2.4-kb transcript encoding a 592-amino-acid protein with 95% identity to the human FZD9. Fzd9 was mapped to the conserved syntenic region on distal mouse chromosome 5. By RNA in situ hybridization studies of whole-mount embryos and sections we delineated the temporal and spatial expression patterns in the neural tube, trunk skeletal muscle precursors (myotomes), limb skeletal anlagen, craniofacial regions, and nephric ducts. In adult mouse tissue, the Fzd9 transcript is abundantly present in heart, brain, testis, and skeletal muscle. In testis, Fzd9 is expressed in all spermatogenic cell types. Immunohistochemical studies of cells transfected with a Fzd9 expression construct confirm that Fzd9 is a membrane protein. These results suggest potential Wnt ligands of Fzd9, a role of Fzd9 in skeletal muscle specification, and contributions of FZD9 to the WBS phenotype.
Wang
Y K
YK
Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA.
Spörle
R
R
Paperna
T
T
Schughart
K
K
Francke
U
U
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004622:Embryo, Mammalian / Q000378:metabolism; D051157:Frizzled Receptors; D017353:Gene Deletion; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000276:immunology; D043562:Receptors, G-Protein-Coupled; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D019170:Somites / Q000378:metabolism; D013737:Testis / Q000196:embryology / Q000378:metabolism; D014018:Tissue Distribution; D018980:Williams Syndrome / Q000235:genetics*
D018076:DNA, Complementary; C105574:FZD3 protein, human; D051157:Frizzled Receptors; C486339:Fzd3 protein, mouse; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled