Involvement of Tcf/Lef in establishing cell types along the animal-vegetal axis of sea urchins

• Published in: Development genes and evolution Vol. 210; no. 2; pp. 73 - 81
• Main Authors: Huang, L, Li, X, El-Hodiri, H M, Dayal, S, Wikramanayake, A H, Klein, W H
• Format: Journal Article
• Language: English
• Published: Germany Springer Nature B.V 01.02.2000
• Subjects: Amino Acid Sequence; Animals; Base Sequence; beta -catenin; Cell Lineage; Cells; Cloning, Molecular; Cytoskeletal Proteins - metabolism; DNA-Binding Proteins - genetics; Gene expression; Gene Expression Regulation, Developmental; High Mobility Group Proteins - chemistry; High Mobility Group Proteins - genetics; Lymphoid Enhancer-Binding Factor 1; Marine; Microinjections; Molecular Sequence Data; Mutation; Phylogeny; RNA, Messenger - metabolism; Sea Urchins - embryology; Sea Urchins - genetics; Sequence Homology, Amino Acid; Strongylocentrotus purpuratus; Tcf/Lef protein; Trans-Activators; Transcription Factors - genetics
• ISSN: 0949-944X; 1432-041X
• DOI: 10.1007/s004270050013

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.