Characterization of thyroid hormones and thyroid hormone receptors during the early development of Pacific bluefin tuna (Thunnus orientalis).

Full Abstract

We studied the profiles of 3,5,3'-l-triiodothyronine (T3), thyroxine (T4), and thyroid hormone receptors (TRs) in Pacific bluefin tuna (Thunnus orientalis) during embryonic and post-embryonic development. Both T3 and T4 were detected in embryos just before hatching, and it was found that the levels of both were increased in postflexion fish. The thyroid follicles were increased in both size and number in postflexion fish compared with preflexion fish. A TRbeta cDNA clone was generated by RACE. Two TRalpha cDNA clones were also partially identified and analyzed by real-time RT-PCR in this study. The TR mRNA levels in embryos were determined, and these were found to be lower than those in preflexion fish. Therefore, we considered that thyroid hormones function during early post-embryonic development as well as during embryonic development. Moreover, there was a peak in the TR mRNA level during postflexion stages, as seen during metamorphosis in Japanese flounder and Japanese conger eel. It is possible that thyroid hormones control the early development of scombrid fish through TRs, as they do for Pluronectiformes and Anguilliformes.

Author information

Author/s: Kawakami, Yutaka (Y); Nozaki, Jun (J); Seoka, Manabu (M); Kumai, Hidemi (H); Ohta, Hiromi (H);

Affiliation: Department of Fisheries, Graduate School of Agriculture, Kinki University, Nara 631-8505, Japan. yutakakjp(-atsign-)yahoo.co.jp

Journal and publication information

Publication Type: Journal Article

Journal: General and comparative endocrinology (Gen Comp Endocrinol), published in United States. (Language: eng)

Reference: 2008-Feb; vol 155 (issue 3) : pp 597-606

Dates: Created 2008/02/11; Completed 2008/05/01;

PMID: 17988667, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.