The putative wnt receptor Xenopus frizzled-7 functions upstream of beta-catenin in vertebrate dorsoventral mesoderm patterning.
We have isolated one member of the frizzled family of wnt receptors from Xenopus (Xfz7) to study the role of cell-cell communication in the establishment of the vertebrate axis. We demonstrate that this maternally encoded protein specifically synergizes with wnt proteins in ectopic axis induction. Embryos derived from oocytes depleted of maternal Xfz7 RNA by antisense oligonucleotide injection are deficient in dorsoanterior structures. Xfz7-depleted embryos are deficient in dorsal but not ventral mesoderm due to the reduced expression of the wnt target genes siamois, Xnr3 and goosecoid. These signaling defects can be restored by the addition of beta-catenin but not Xwnt8b. Xfz7 thus functions upstream of the known GSK-3/axin/beta-catenin intracellular signaling complex in vertebrate dorsoventral mesoderm specification.
Sumanas
S
S
University of Minnesota Medical School, Department of Genetics, Cell Biology, Institute of Human Genetics, Room 6-160 Jackson Hall, Minneapolis, MN 55455, USA.
Strege
P
P
Heasman
J
J
Ekker
S C
SC
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning; D003598:Cytoskeletal Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D051956:Goosecoid Protein; D018398:Homeodomain Proteins / Q000235:genetics; D008648:Mesoderm / Q000378:metabolism; D008845:Microinjections; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016372:RNA, Antisense / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled; D012097:Repressor Proteins; D015398:Signal Transduction; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta / Q000235:genetics; D051153:Wnt Proteins; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; D051176:beta Catenin
C495266:CTNNB1 protein, Xenopus; D003598:Cytoskeletal Proteins; C492040:Fzd7 protein, Xenopus; D051956:Goosecoid Protein; D018398:Homeodomain Proteins; D011518:Proto-Oncogene Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D012097:Repressor Proteins; C093133:SIA1 protein, Xenopus; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; D051176:beta Catenin; C094620:nodal3.1 protein, Xenopus