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Expression of Islet1 in thyroid development related to budding, migration, and fusion of primordia
Author(s) -
Westerlund Jessica,
Andersson Louise,
Carlsson Therese,
Zoppoli Pietro,
Fagman Henrik,
Nilsson Mikael
Publication year - 2008
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.21772
Subject(s) - biology , endoderm , thyroid , embryonic stem cell , progenitor cell , pax8 , homeobox , microbiology and biotechnology , organogenesis , progenitor , medicine , endocrinology , stem cell , transcription factor , gene , genetics
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. Developmental Dynamics 237:3820–3829, 2008. © 2008 Wiley‐Liss, Inc.