title: An iodothyronine deiodinase from Chlamys farreri and its induced mRNA expression after LPS stimulation.
abstract: Iodothyronine deiodinase is responsible for the deiodination of thyroxine T4 to T3, and involved in the complex neuroendocrine-immune regulatory network to optimize the immune response in vertebrate. In this study, the full-length cDNA of an iodothyronine deiodinase (designated as CfDx) was cloned from scallop Chlamys farreri. The complete cDNA sequence of CfDx was of 1404 bp and contained an open reading frame of 900 bp encoding a polypeptide of 299 amino acids. The deduced amino acid sequence of CfDx contained an in-frame TGA stop codon probably encoding an essential selenocysteine (SeC), and there was a conserved region of about 15 amino acids surrounding the SeC residue. The CfDx mRNA transcripts were detected in all the tested tissues, including haemocytes, hepatopancreas, kidney, adductor muscle, gonad, gill and mantle, with the higher expression level in hepatopancreas and kidney. After LPS stimulation, the CfDx mRNA expression level in haemocytes increased significantly at 12 h (25.35-fold, P < 0.05) and 24 h (7.62-fold, P < 0.05), and the concentration of T3 in haemolymph increased significantly at 12 h (3.62 ng dL(-1), P < 0.05) even the concentration of T4 did not change significantly. After scallop received an injection of 50 μg CfDx dsRNA, the expression level of CfDx mRNA in haemocytes began to decrease significantly at 36 h and maintained the relative low level (about 0.3-fold of the PBS control group) from 36 to72 h, but the ratio of T4/T3 in haemolymph began to increase at 36 h (2.31-fold, P < 0.05) and kept increasing from 36 to 72 h comparing with that in the PBS control group. These results indicated that CfDx was a homologue of iodothyronine deiodinase in scallop C. farreri, and it might be involved in the immunomodulation via regulating the concentration of thyroid hormones T3 and T4 in the haemolymph of scallop.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Wu
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Shi
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhou
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.forename: Mengqiang
authors.initials: M
authors.lastname: Wang
authors.forename: Leilei
authors.initials: L
authors.lastname: Wang
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Huang
authors.forename: Chuanyan
authors.initials: C
authors.lastname: Yang
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006434:Hemocytes / Q000187:drug effects / Q000201:enzymology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D049897:Pectinidae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D013997:Time Factors
chemical_list: D008070:Lipopolysaccharides; D012333:RNA, Messenger