Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791, South Korea.
Comp Biochem Physiol C Toxicol Pharmacol. 2010 Apr;151(3):303-12. doi: 10.1016/j.cbpc.2009.12.003. Epub 2009 Dec 16.
Ecdysteroids are steroid hormones that play an important role in development, growth, molting of larva, and reproduction in the Arthropoda. The effect of ecdysteroids is mediated by its binding to ecdysteroid receptor (EcR). To investigate the role of EcR during development and the effect to environmental stressors on EcR expression in a copepod, we isolated and characterized cDNA and 5'-promoter region of the Tigriopus japonicus EcR (TJ-EcR), and studied mRNA expression pattern. The full-length TJ-EcR cDNA sequence was 1962bp in length and the open reading frame encoded 546 amino acids. The deduced TJ-EcR protein contained well-conserved DNA-binding domain and ligand-binding domain. Phylogenetic analysis revealed that TJ-EcR was clustered with the EcR of other crustaceans. TJ-EcR mRNA was expressed in a developmental stage-specific manner: high in early developmental stages and low in the adult stage. Significantly elevated expression of the TJ-EcR gene in adults was detected at hypersalinity (42ppt) and high temperature (35 degrees C) condition. The 5'-flanking region of TJ-EcR gene contains heat shock protein 70 response elements, implying that the environmental stressors may affect its expression via the stress-sensor. In addition, bisphenol A (100microg/L) repressed TJ-EcR expression. Our results suggest that TJ-EcR could be a biomarker for the monitoring of the impact of environmental stressors in copepods.
蜕皮甾酮是甾族激素，在节肢动物的发育、生长、幼虫蜕皮和繁殖中起着重要作用。蜕皮甾酮的作用是通过与蜕皮甾酮受体（EcR）结合来介导的。为了研究 EcR 在发育过程中的作用以及环境胁迫因子对桡足类 EcR 表达的影响，我们分离并鉴定了中华哲水蚤 EcR（TJ-EcR）的 cDNA 和 5'-启动子区，并研究了其 mRNA 表达模式。TJ-EcR cDNA 全长 1962bp，开放阅读框编码 546 个氨基酸。推导的 TJ-EcR 蛋白含有高度保守的 DNA 结合域和配体结合域。系统发育分析表明，TJ-EcR 与其他甲壳类动物的 EcR 聚类在一起。TJ-EcR mRNA 在发育阶段具有特异性表达：早期发育阶段高，成年阶段低。在高盐度（42ppt）和高温（35 摄氏度）条件下，成虫 TJ-EcR 基因的表达显著升高。TJ-EcR 基因的 5'-侧翼区含有热休克蛋白 70 反应元件，这意味着环境胁迫因子可能通过应激传感器影响其表达。此外，双酚 A（100μg/L）抑制了 TJ-EcR 的表达。我们的结果表明，TJ-EcR 可以作为桡足类动物监测环境胁迫因子影响的生物标志物。
