| RRC ID |
31780
|
| Author |
Nakajima K, Fujimoto K, Yaoita Y.
|
| Title |
Regulation of thyroid hormone sensitivity by differential expression of the thyroid hormone receptor during Xenopus metamorphosis.
|
| Journal |
Genes Cells
|
| Abstract |
During amphibian metamorphosis, a series of dynamic changes occur in a predetermined order. Hind limb morphogenesis begins in response to low levels of thyroid hormone (TH) in early prometamorphosis, but tail muscle cell death is delayed until climax, when TH levels are high. It takes about 20 days for tadpoles to grow from early prometamorphosis to climax. To study the molecular basis of the timing of tissue-specific transformations, we introduced thyroid hormone receptor (TR) expression constructs into tail muscle cells of Xenopus tadpoles. The TR-transfected tail muscle cells died upon exposure to a low level of thyroxine (T4). This cell death was suggested to be mediated by type 2 iodothyronine deiodinase (D2) that converts T4 to T3-the more active form of TH. D2 mRNA was induced in the TR-overexpressing cells by low levels of TH. D2 promoter contains a TH-response element (TRE) with a lower affinity for TR. These results show that the TR transfection confers the ability to respond to physiological concentrations of TH at early prometamorphosis to tail muscle cells through D2 activity and promotes TH signaling. We propose the positive feedback loop model to amplify the cell's ability to respond to low levels of T4.
|
| Volume |
17(8)
|
| Pages |
645-59
|
| Published |
2012-8-1
|
| DOI |
10.1111/j.1365-2443.2012.01614.x
|
| PMID |
22686326
|
| MeSH |
Animals
Cell Death
Electrophoretic Mobility Shift Assay
Feedback, Physiological
Gene Expression Regulation, Developmental*
Green Fluorescent Proteins / genetics
Green Fluorescent Proteins / metabolism
Hindlimb / metabolism
Iodide Peroxidase / metabolism
Larva / genetics
Larva / growth & development
Metamorphosis, Biological*
Microinjections
Muscle Cells / cytology
Muscle Cells / drug effects
Muscle Cells / metabolism
Promoter Regions, Genetic
RNA, Messenger / genetics
RNA, Messenger / metabolism
Receptors, Thyroid Hormone / drug effects
Receptors, Thyroid Hormone / metabolism*
Signal Transduction
Tail / cytology
Tail / metabolism
Thyroxine / metabolism
Thyroxine / pharmacology*
Time Factors
Transcriptome
Transfection
Triiodothyronine / metabolism
Xenopus laevis / genetics
Xenopus laevis / growth & development
|
| IF |
1.655
|
| Times Cited |
23
|
|
WOS Category
|
GENETICS & HEREDITY
CELL BIOLOGY
|
| Resource |
| Clawed frogs / Newts |
Ivory Coast line |
