Alteration of thyroid hormone levels and related gene expression in Chinese rare minnow larvae exposed to mercury chloride.
Mercury is a prominent environmental contaminant that causes endocrine disorder to human and other organisms. But little is known about the response of the thyroid functions and hypothalamic-pituitary-thyroid (HPT) axis to mercury in teleosts and the few studies that are available have not yielded consistent results. In this study, expression profiles of corticotropin-releasing hormone (crh), thyroid stimulating hormone beta (tshβ), solute carrier family 5 (sodium iodide symporter) member 5 (slc5a5), thyroglobulin (tg), thyroid hormone receptor alpha (trα) and thyroid hormone receptor beta (trβ) genes were determined in whole-body of Chinese rare minnow (Gobiocypris rarus) larvae after exposure to different levels of Hg(2+) (0, 0.1 and 0.3 mg/l) for 4 days, as well as the thyroid hormones (THs) levels. Moreover, the 96-h lethal concentration of Hg(2+) on rare minnow larvae was determined as 0.32 mg/l. The results showed that crh, tg, trα and trβ mRNA levels were significantly up-regulated in the larvae, but the gene expression of tshβ and slc5a5 was not significantly changed in our study. Besides, the THs levels increased in the whole-body of fish, especially the thyroxine (T4) level. The above results indicated that Hg(2+) could alter some genes expression in the HPT axis which could be used as the potential biomarkers for evaluating the environmental Hg(2+)-induced stress in fish.
['Li|Zhi-Hua|ZH|', 'Chen|Lu|L|', 'Wu|Yan-Hua|YH|', 'Li|Ping|P|', 'Li|Yun-Feng|YF|', 'Ni|Zhao-Hui|ZH|']
D000818:Animals D003346:Corticotropin-Releasing Hormone D003530:Cyprinidae D005786:Gene Expression Regulation D007814:Larva D007928:Lethal Dose 50 D008627:Mercuric Chloride D027981:Symporters D013954:Thyroglobulin D037021:Thyroid Hormone Receptors alpha D037042:Thyroid Hormone Receptors beta D037322:Thyrotropin, beta Subunit D013974:Thyroxine D014284:Triiodothyronine D014874:Water Pollutants, Chemical
Thyroid hormone Gene expression Chinese rare minnow Mercury Hypothalamic–pituitary–thyroid axis