鋅離子對於人體及其他生物而言，屬於必需微量元素之一，參與了各種不同生化途徑，其中包含生長發育的過程。鋅運輸蛋白依功能歸類為兩族群：ZnT (scl30a)蛋白從細胞質內移除游離的鋅離子，ZIP (slc30a)蛋白則將鋅離子往細胞質內運送，藉以調控鋅離子的恆定。ZIP家族中的ZIP8除了已知可運輸鋅離子外，被發現可同時做為硒離子的通道蛋白。硒離子同樣是生物體所必須的微量元素，並是組成硒相關蛋白結構中的主要成分，部分硒相關蛋白與氧化壓力的調節相關。其中glutathione peroxidase 1 (gpx1) 與selenoprotein P1 (sepp1) 在哺乳類動物與硬骨魚中具有同源關係，gpx1參與抗氧化的功能，sepp1運輸血液中的硒離子。在人體及斑馬魚中，硒相關蛋白表現量皆受硒離子濃度改變而有所影響。有鑑於ZIP8對硒離子所俱備的運輸功能，及硒相關蛋白基因在哺乳類及硬骨魚之間的同源關係，此篇研究針對ZIP8是否影響硒相關蛋白表現量做進一步的探討，發現ZIP8受抑制時，gpx1b在72小時有明顯大量表現，而gpx1a及gpx3在各時間點皆呈現下降的趨勢；sepp1a則是在60小時表現量明顯上升，其餘時期與sepp1b相同均受到負調控的影響。透過結果可知硒相關蛋白表現量確實會因ZIP8的抑制而受到影響，而其中機制與相互關係仍需探討。
Zinc is one of the essential micronutrients for organisms. It participates in biochemical pathways including the process of development. Zinc transporters can be classified into two families, and are involving the regulations of zinc homeostasis in organisms. ZnT proteins are responsible for removing the free zinc from cytoplasm, and ZIP proteins are functioning as a tunnel for extracellular zinc uptake. Among them, ZIP8, was also identified as the transporter of selenium, another essential micronutrient for normal function in organisms and usually work as the form composed with selenoproteins. These selenoproteins are separated into two groups, stress-related proteins and housekeeping proteins. Several genes of them are paralogues between mammalian and teleost fish such as glutathione peroxidase 1 (gpx1) and selenoprotein P1 (sepp1). Proteins of gpx1 work as the role for antioxidant and sepp1 is participated in transporting selenium in blood. In zebrafish, the expression of selenoproteins mentioned above are respond to the change of selenium level. Because of the selenium-transporting ability of ZIP8 and the paralogues relation of selenoproteins between mammalian and zebrafish, the effect of ZIP8 on the expression of selenoproteins was investigated. According to the results, gpx1b expression raised in 72hpf when ZIP8 was knockdown, and gpx1a and gpx3 decreased at the same time. Expression of sepp1a increased in 60hpf, and sepp1b decreased form 24hpf to 72hpf. It can tell that the expression of these selenoproteins are affected by ZIP8-knockdown, and the mechanism should be studied in the future.
