title: Expression of Islet1 in thyroid development related to budding, migration, and fusion of primordia.
abstract: The LIM homeodomain transcription factor Isl1 was investigated in mouse thyroid organogenesis. All progenitor cells of the midline thyroid diverticulum and lateral primordia (ultimobranchial bodies) expressed Isl1. This pattern persisted until the growing anlagen fused at embryonic day (E) 13.5. In Isl1 null mutants thyroid progenitors expressing Nkx2.1 and Pax8 were readily specified in the anterior endoderm but the size of the thyroid rudiment was reduced. In late development, only immature C-cells expressed Isl1. In the adult gland the number of Isl1+ cells was small compared with cells expressing calcitonin. Analysis of microarray profiles indicated a higher level of Isl1 expression in medullary thyroid carcinomas than in tumors derived from follicular cells. Together, these findings suggest that Isl1 may be a novel regulator of thyroid development before terminal differentiation of the endocrine cell types. Isl1 is an embryonic C-cell precursor marker that may be relevant also in cancer developed from the mature C-cell.
authors.affiliation: Department of Medical Chemistry and Cell Biology, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden. jessica.westerlund@anatcell.gu.se
authors.forename: Jessica
authors.initials: J
authors.lastname: Westerlund
authors.forename: Louise
authors.initials: L
authors.lastname: Andersson
authors.forename: Therese
authors.initials: T
authors.lastname: Carlsson
authors.forename: Pietro
authors.initials: P
authors.lastname: Zoppoli
authors.forename: Henrik
authors.initials: H
authors.lastname: Fagman
authors.forename: Mikael
authors.initials: M
authors.lastname: Nilsson
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D018276:Carcinoma, Medullary / Q000235:genetics; D002465:Cell Movement; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D060850:LIM-Homeodomain Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013234:Stem Cells / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000235:genetics; D014157:Transcription Factors
chemical_list: D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1