Molecular cloning and sequence analysis of chicken type I deiodinase cDNA: expression in normal and dwarf broiler chickens.
A cDNA encoding the chicken type I iodothyronine deiodinase (cDI-1) was isolated and sequenced from a cDNA library prepared from ConA-activated chicken splenic T-lymphocytes. The coding region of cDI-1 cDNA is composed of 738 basepairs (bp) which encodes a 246 amino acid protein. The predicted amino acid sequence of cDI-1 indicates only 60% identity to several mammalian type I deiodinases. The cDI-1 cDNA contains a codon for a highly conserved selenocysteine residue (Cys124). Northern blot analysis of total RNA prepared from different tissues of a 3-week-old broiler chicken shows a single transcript (2 kb) in liver and kidney. The abundance of hepatic cDI-1 transcripts in growth hormone receptor (GHR)-deficient dwarf chicken was similar to normal chickens despite lower levels of plasma T3 (37% lower) and elevated levels of T4 (21% higher) in dwarf chickens. This finding suggests that regulation of hepatic cDI-1 mRNA is GH-independent in the post-hatch chicken.
Cogburn
L A
LA
Department of Animal and Food Sciences, Delaware Agricultural Experiment Station, College of Agricultural Sciences, University of Delaware, Newark 19717-1303, USA. cogburn@udel.edu
Sofer
L
L
Burnside
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000254:growth & development; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D004392:Dwarfism / Q000235:genetics*; D015870:Gene Expression; D008040:Genetic Linkage; D007453:Iodide Peroxidase / Q000235:genetics*; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008969:Molecular Sequence Data; D011986:Receptors, Somatotropin / Q000235:genetics; D017279:Selenocysteine / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012729:Sex Chromosome Aberrations / Q000235:genetics; D013045:Species Specificity; D013154:Spleen / Q000166:cytology
D018076:DNA, Complementary; D011986:Receptors, Somatotropin; D017279:Selenocysteine; C109812:iodothyronine deiodinase type I; D007453:Iodide Peroxidase