Han Ying-Li, Sheng Zhang, Liu Guo-Di, Long Ling-Li, Wang You-Fa, Yang Wan-Xi, Zhu Jun-Quan
School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China.
The Sperm Laboratory, College of life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China.
Ecotoxicol Environ Saf. 2015 Sep;119:1-8. doi: 10.1016/j.ecoenv.2015.04.055. Epub 2015 May 14.
Metallothioneins (MTs) are cysteine-rich, low molecular weight, and heavy metal-binding protein molecules. MT participates in metallic homeostasis and detoxification in living animals due to its abundant cysteine. In order to investigate the functions of MT during spermiogenesis in the mudskipper (Boleophthalmus pectinirostris), we identified the MT complete which contains: an 83bp 5' untranslated region, a 110bp 3' untranslated region, and a 183bp open reading frame. The protein alignment between MT sequences of other species shows a high similarity and a strong identity in cysteine residues vital for the metal-binding affinity of MT. The localizations of MT were mainly in the cytoplasm of germinal cells, indicating a role in spermatogenesis and testis protection. After the cadmium (Cd) exposure, the testis presents abnormal morphology and MT mRNA expression, both of which indicate a sensitive response of testis MT to Cd. Therefore, we suggest that MTs play an important role in spermatogenesis and testes protection against Cd toxicity in B. pectinirostris.
金属硫蛋白（MTs）是富含半胱氨酸、低分子量的重金属结合蛋白分子。由于MT富含半胱氨酸，它参与活体动物的金属稳态和解毒过程。为了研究弹涂鱼（大弹涂鱼）精子发生过程中MT的功能，我们鉴定出MT的完整序列，其包含：一个83bp的5'非翻译区、一个110bp的3'非翻译区和一个183bp的开放阅读框。其他物种MT序列之间的蛋白质比对显示出高度相似性，并且在对MT金属结合亲和力至关重要的半胱氨酸残基上具有很强的一致性。MT的定位主要在生殖细胞的细胞质中，表明其在精子发生和睾丸保护中发挥作用。镉（Cd）暴露后，睾丸呈现出异常形态和MT mRNA表达，这两者均表明睾丸MT对Cd有敏感反应。因此，我们认为MTs在大弹涂鱼的精子发生以及睾丸抵御Cd毒性的保护过程中发挥重要作用。
