title: Expression of the AmphiTcf gene in amphioxus: insights into the evolution of the TCF/LEF gene family during vertebrate evolution.
abstract: T-cell factor (TCF) and lymphoid enhancer factors (LEF) genes encode proteins that are transcription factors mediating beta-catenin/Wnt signaling. Whereas mammals have four such genes, the Florida amphioxus (Branchiostoma floridae) apparently has only one such gene (AmphiTcf). From cleavage through early gastrula, cytoplasmic maternal transcripts of this gene are localized toward the animal pole. In gastrulae, AmphiTcf expression begins in the mesendoderm. In neurulae, there is expression in the pharynx, hindgut, anterior notochord, somites, and at the anterior end of the neural plate. In early larvae, expression is detectable in the floor of the diencephalon, notochord, tail bud, forming somites, pharynx, and ciliated pit (a presumed homolog of the vertebrate adenohypophysis). Phylogenetic analysis of TCF/LEF proteins placed AmphiTcf as the sister group of a clade comprising vertebrate Tcf1, Lef1, Tcf3, and Tcf4. Comparison of developmental expression for amphioxus AmphiTcf and vertebrate TCF/LEF genes indicates that this gene family has undergone extensive subfunctionalization and neofunctionalization during vertebrate evolution.
authors.affiliation: Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093, USA. h3lin@ucsd.edu
authors.forename: Hsiu-Chin
authors.initials: HC
authors.lastname: Lin
authors.forename: Linda Z
authors.initials: LZ
authors.lastname: Holland
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Holland
mesh_terms: D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D002816:Chordata, Nonvertebrate / Q000196:embryology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D005810:Multigene Family; D010802:Phylogeny; D051820:TCF Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D014714:Vertebrates / Q000235:genetics; D051176:beta Catenin / Q000378:metabolism
chemical_list: D017931:DNA Primers; D051820:TCF Transcription Factors; D051176:beta Catenin