BACKGROUND Zn is an essential trace element for vertebrates, and Zn uptake and transport is related with the ZIP family of Zn transporters. Meantime, Zn also influenced the expression of ZIP family members. METHODS We cloned and characterized the full-length cDNA sequences of ten Zn transport-relevant genes (ZIP1, ZIP3, ZIP6, ZIP7, ZIP8, ZIP9, ZIP10, ZIP11, ZIP13 and ZIP14) from yellow catfish Pelteobagrus fulvidraco, investigated their mRNA tissue expression. These ZIP mRNA expression was also assessed in the primary hepatocytes and intestinal epithelial cells of yellow catfish in response to three Zn levels (0, 30 μM and 60 μM, respectively). RESULTS All these genes shared the similar domains with the corresponding members in mammals. The mRNA expression of the ten ZIP genes was detected in nine-tested tissues, but variable among these tissues. Flow cytometry analysis and confocal microscopy observation indicated that intracellular free Zn2+ concentration in hepatocytes and intestinal epithelial cells increased with increasing Zn incubation concentration at both 24 h and 48 h. Zn incubation differentially influenced mRNA levels of ZIP transporters in the hepatocytes and intestinal epithelial cells, in a time- and cells-dependent manners. In the hepatocytes, at 24 h, compared to the control, Zn addition down-regulated mRNA levels of ZIP1, ZIP3, ZIP6, ZIP7, ZIP8, ZIP9, ZIP11 and ZIP14; however, ZIP10 mRNA levels were lower in 60 μM Zn group than those in the control and 30 μM Zn group. At 48 h, mRNA levels of ZIP1, ZIP6, ZIP7, ZIP9, ZIP10 and ZIP14 declined with increasing Zn incubation concentrations; ZIP3 mRNA levels were the lowest in 60 μM Zn group and showed no significant differences between the control and 30 μM Zn group. In the intestinal epithelial cells, at 24 h, Zn addition down-regulated mRNA levels of ZIP1, ZIP6, ZIP7, ZIP8, ZIP9, ZIP10, ZIP11, ZIP13 and ZIP14; ZIP3 mRNA levels were lower in 60 μM Zn group than those in the control and 30 μM Zn group. At 48 h, Zn addition up-regulated mRNA levels of ZIP6 and ZIP9, but down-regulated mRNA levels of ZIP8, ZIP10 and ZIP13. ZIP7, ZIP11 and ZIP14 mRNA abundances were the lowest in 60 μM Zn group and showed no significant differences between the control and 30 μM Zn group. CONCLUSION For the first time, our study characterized ten ZIP family members in yellow catfish, explored their mRNA tissue expression. Their regulation to Zn addition were also investigated in the hepatocytes and intestinal epithelial cells of yellow catfish. Our study revealed the mechanism of cells exposed to Zn addition and provided novel insights for the regulatory mechanism of Zn homeostasis.

中文翻译：

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淡水硬骨黄cat鱼Pelteobagrus fulvidraco中十个锌（Zn）转运蛋白基因的分子特征及其对锌代谢的调控。

背景技术Zn是脊椎动物的必需微量元素，Zn的吸收和运输与Zn转运蛋白的ZIP家族有关。同时，Zn也影响ZIP家族成员的表达。方法我们克隆并鉴定了十个与transport运输相关的基因（ZIP1，ZIP3，ZIP6，ZIP7，ZIP8，ZIP9，ZIP10，ZIP11，ZIP13和ZIP14）的全长cDNA序列，并研究了它们的mRNA组织表达。 。在三个ZIP水平（分别为0、30μM和60μM）的响应下，黄cat鱼的初级肝细胞和肠上皮细胞也评估了这些ZIP mRNA表达。结果所有这些基因与哺乳动物中的相应成员共享相似的结构域。在9个经过测试的组织中检测到10个ZIP基因的mRNA表达，但在这些组织之间存在差异。流式细胞仪分析和共聚焦显微镜观察表明，在24 h和48 h时，肝细胞和肠上皮细胞中细胞内游离Zn2 +的浓度均随Zn浓度的增加而增加。锌孵育以时间和细胞依赖性方式差异影响肝细胞和肠上皮细胞中ZIP转运蛋白的mRNA水平。在肝细胞中，与对照组相比，在24小时时，Zn的添加下调了ZIP1，ZIP3，ZIP6，ZIP7，ZIP8，ZIP9，ZIP11和ZIP14的mRNA水平。然而，60μMZn组的ZIP10 mRNA水平低于对照组和30μMZn组。在48小时时，随着Zn孵育浓度的增加，ZIP1，ZIP6，ZIP7，ZIP9，ZIP10和ZIP14的mRNA水平下降。在60μMZn组中，ZIP3 mRNA水平最低，并且对照组和30μMZn组之间无显着差异。在肠上皮细胞中，在24 h时，Zn的添加下调了ZIP1，ZIP6，ZIP7，ZIP8，ZIP9，ZIP10，ZIP11，ZIP13和ZIP14的mRNA水平。60μMZn组的ZIP3 mRNA水平低于对照组和30μMZn组的ZIP3 mRNA水平。在第48小时，锌的添加上调了ZIP6和ZIP9的mRNA水平，但下调了ZIP8，ZIP10和ZIP13的mRNA水平。在60μMZn组中，ZIP7，ZIP11和ZIP14 mRNA的丰度最低，而对照组和30μMZn组之间无显着差异。结论我们的研究首次对黄色cat鱼中的十个ZIP家族成员进行了表征，探讨了它们的mRNA组织表达。还研究了黄cat鱼肝细胞和肠上皮细胞中锌对锌添加的调控。我们的研究揭示了暴露于锌添加的细胞的机制，并为锌稳态的调节机制提供了新的见解。