title: Activation of Sox3 gene by thyroid hormone in the developing adult intestinal stem cell during Xenopus metamorphosis.
abstract: The maturation of the intestine into the adult form involves the formation of adult stem cells in a thyroid hormone (T3)-dependent process in vertebrates. In mammals, this takes place during postembryonic development, a period around birth when the T3 level peaks. Due to the difficulty of manipulating late-stage, uterus-enclosed embryos, very little is known about the development of the adult intestinal stem cells. Interestingly, the remodeling of the intestine during the T3-dependent amphibian metamorphosis mimics the maturation of mammalian intestine. Our earlier microarray studies in Xenopus laevis revealed that the transcription factor SRY (sex-determining region Y)-box 3 (Sox3), well known for its involvement in neural development, was upregulated in the intestinal epithelium during metamorphosis. Here, we show that Sox3 is highly and specifically expressed in the developing adult intestinal progenitor/stem cells. We further show that its induction by T3 is independent of new protein synthesis, suggesting that Sox3 is directly activated by liganded T3 receptor. Thus, T3 activates Sox3 as one of the earliest changes in the epithelium, and Sox3 in turn may facilitate the dedifferentiation of the larval epithelial cells into adult stem cells.
authors.affiliation: School of Basic Medical Sciences (G.S.), Wuhan University, Wuhan 430072, People's Republic of China; and Section on Molecular Morphogenesis (L.F., L.W., Y.-B.S.), Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Guihong
authors.initials: G
authors.lastname: Sun
authors.forename: Liezhen
authors.initials: L
authors.lastname: Fu
authors.forename: Luan
authors.initials: L
authors.lastname: Wen
authors.forename: Yun-Bo
authors.initials: YB
authors.lastname: Shi
mesh_terms: D053687:Adult Stem Cells / Q000502:physiology*; D000818:Animals; D004848:Epithelium / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007422:Intestines / Q000254:growth & development; D008675:Metamorphosis, Biological; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014284:Triiodothyronine / Q000502:physiology*; D014981:Xenopus; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D055748:SOXB1 Transcription Factors; C527788:Sox3 protein, Xenopus; D029867:Xenopus Proteins; D014284:Triiodothyronine