Thyroid-specific enhancer-binding protein/thyroid transcription factor 1 is not required for the initial specification of the thyroid and lung primordia.
Targeted disruption of the homeobox gene T/ebp (Ttf1) in mice results in ablation of the thyroid and pituitary, and severe deformities in development of the lung and hypothalamus. T/ebp is expressed in the thyroid, lung, and ventral forebrain during normal embryogenesis. Examination of thyroid development in T/ebp homozygous null mutant embryos revealed that the thyroid rudiment is initially formed but is eliminated through apoptosis. Absence of T/EBP expression in the lung primordium does not activate apoptosis since a lung tissue, albeit dysmorphic, is nevertheless formed in T/ebp-/- embryos. These results demonstrate that T/EBP is not required for the initial specification of thyroid or lung primordia, but is absolutely essential for the development and morphogenesis of these organs.
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Kimura
J M
JM
Ward
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Minoo
D000818:Animals; D005314:Embryonic and Fetal Development; D004848:Epithelium; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D008168:Lung / Q000196:embryology* / Q000473:pathology; D008648:Mesoderm; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D010902:Pituitary Gland / Q000196:embryology; D013961:Thyroid Gland / Q000196:embryology* / Q000473:pathology; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
D018398:Homeodomain Proteins; C000614414:Nkx2-1 protein, mouse; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors