Science Inventory

Characterization of Thyroid Hormone Transporter Protein Expression during Tissue-specific Metamorphic Events in Xenopus tropicalis

Citation:

CONNORS, K., J. J. KORTE, G. ANDERSON, AND S. J. DEGITZ. Characterization of Thyroid Hormone Transporter Protein Expression during Tissue-specific Metamorphic Events in Xenopus tropicalis . GENERAL AND COMPARATIVE ENDOCRINOLOGY. Academic Press Incorporated, Orlando, FL, 168(1):149-159, (2010).

Impact/Purpose:

To document research results.

Description:

Thyroid hormone (TH) induces the dramatic morphological and physiological changes that together comprise amphibian metamorphosis. TH-responsive tissues vary widely with developmental timing of TH-induced changes. How larval tadpole tissues are able to employ distinct metamorphic programs in a developmental stage- and TH-dependent manner is still unknown. Recently, several proteins capable of transporting TH have been identified. TH action and metabolism occurs primarily intracellularly, highlighting the importance of TH transporters. We examined the hypothesis that TH transporter expression and tissue distribution may play an important role in mediating TH-induced metamorphic events. Xenopus tropicalis homologs for known TH transporting OATP, MCT and LAT family proteins were identified and gene specific qRT-PCR primers were developed. Total RNA was extracted from tissues representing three unique developmental fates including: growth/differentiation (hind limb), death/resorption (gill, tail) and remodeling (liver, kidney). For growing and resorbing tissues, results showed the general trend of low initial expression levels of MCT8 and MCT10 transporters, followed by a several-fold increase of expression as the tissue undergoes TH-dependent metamorphic changes. The expression pattern in remodeling tissues was less uniform: a general decrease in transporter expression was observed in the liver, while the kidney exhibited a range of expression patterns for several TH transporters. Collectively, these developmental expression patterns are consistent with TH transporting proteins playing a role in the effects of TH in peripheral tissues.

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Product Published Date: 08/01/2010
Record Last Revised: 09/23/2011
OMB Category: Other
Record ID: 217789

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LABORATORY

MID-CONTINENT ECOLOGY DIVISION

MOLECULAR & CELLULAR MECHANISMS RESEARCH