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.
Kimura
S
S
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Ward
J M
JM
Minoo
P
P
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