Involvement of Tcf/Lef in establishing cell types along the animal-vegetal axis of sea urchins.
Members of the Tcf/Lef family interact with beta-catenin to activate programs of gene expression during development. Recently beta-catenin was shown to be essential for establishing cell fate along the animal-vegetal axis of the sea urchin embryo. To examine the role of Tcf/Lef in sea urchins we cloned a Strongylocentrotus purpuratus Tcf/Lef homolog. Expression of SpTcf/Lef was maximal when beta-catenin became localized to nuclei of vegetal blastomeres, consistent with its acting in combination with beta-catenin to specify vegetal cell fates. Expression of a dominant-negative SpTcf/Lef inhibited primary and secondary mesenchyma, endoderm, and aboral ectoderm formation in a manner similar to that observed when nuclear accumulation of beta-catenin was prevented. Our results suggest that SpTcf/Lef functions by interacting with beta-catenin to specify cell fates along the sea urchin animal-vegetal axis.
Huang
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L
Department of Biochemistry and Molecular Biology, M.D. Anderson Cancer Center, University of Texas, 1515 Holcombe Blvd., Houston, TX 77030, USA.
Li
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X
El-Hodiri
H M
HM
Dayal
S
S
Wikramanayake
A H
AH
Klein
W H
WH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019070:Cell Lineage; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006609:High Mobility Group Proteins / Q000737:chemistry / Q000235:genetics; D051821:Lymphoid Enhancer-Binding Factor 1; D008845:Microinjections; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D012617:Sea Urchins / Q000196:embryology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics; D051176:beta Catenin
D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D051821:Lymphoid Enhancer-Binding Factor 1; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; D051176:beta Catenin