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Molecular cloning and expression of thyroid hormone receptor alpha during salmonid development.
- Source :
-
General and comparative endocrinology [Gen Comp Endocrinol] 2002 Feb 01; Vol. 125 (2), pp. 226-35. - Publication Year :
- 2002
-
Abstract
- Thyroid hormones have been implicated as important regulators of teleost development. To gain a better understanding of the potential roles of the thyroid system in salmonids a genomic clone which encoded rainbow trout TR-alpha was isolated. This clone exhibited highest amino acid identity to Japanese flounder TR-alphaB (94%) and zebrafish TR-alpha1 (94%). Oligonucleotides were designed against the rainbow trout sequence and the complete coding region of Atlantic salmon TR-alpha was isolated by RACE-PCR. The Atlantic salmon sequence exhibited highest amino acid identity to rainbow trout TR-alpha (98%), Japanese flounder TR-alphaB (93%), and zebrafish TR-alpha1 (90%). Atlantic salmon TR-alpha exhibited the classic modular structure associated with members of the nuclear receptor superfamily and consisted of a divergent A/B domain while the DNA and ligand-binding domains were highly conserved to other teleost TR proteins. Temporal expression from the rainbow trout TR-alpha gene was monitored by semiquantitative RT-PCR at selected stages during rainbow trout embryonic and larval development. High levels of maternal transcripts were present at cleavage (Stage 6) which were rapidly degraded by gastrulation (Stage 13). Low levels of TR-alpha expression were then detected during organogenesis (Stages 20, 24, 26, 29, and 31). A peak in mRNA levels was observed at hatch (Stage 32) after which levels rose in a gradual manner during larval development (Stages 33, 34, 35, and 36) to reach maximal values at first feeding (Stage 37). These results suggest that the thyroid axis is functional and that embryonic and larval rainbow trout are at least capable of responding to thyroid hormones. These observations implicate the thyroid system as being an important regulator of salmonid development.
- Subjects :
- Amino Acid Sequence
Animals
Base Sequence
DNA-Binding Proteins chemistry
Larva growth & development
Larva metabolism
Molecular Sequence Data
Oncorhynchus mykiss embryology
Oncorhynchus mykiss metabolism
RNA, Messenger analysis
Receptors, Cytoplasmic and Nuclear chemistry
Reverse Transcriptase Polymerase Chain Reaction
Salmo salar embryology
Salmo salar metabolism
Sequence Alignment
Cloning, Molecular
DNA-Binding Proteins genetics
Gene Expression
Oncorhynchus mykiss growth & development
Receptors, Cytoplasmic and Nuclear genetics
Receptors, Thyroid Hormone
Salmo salar growth & development
Subjects
Details
- Language :
- English
- ISSN :
- 0016-6480
- Volume :
- 125
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- General and comparative endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 11884068
- Full Text :
- https://doi.org/10.1006/gcen.2001.7745