Effects of dietary cystine and tyrosine on melanogenesis pathways involved in skin color differentiation of Malaysian red tilapia
Effects of dietary cystine and tyrosine on melanogenesis pathways involved in skin color differentiation of Malaysian red tilapia
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DOI：
10.1016/j.aquaculture.2018.02.023
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发表时间：
2018-03
期刊：
影响因子：
4.5
通讯作者：
Lanmei Wang;Wenbin Zhu;Jie Yang;Linghong Miao;Juanjuan Dong;F. Song;Z. Dong
中科院分区：
文献类型：
--
作者：
Lanmei Wang;Wenbin Zhu;Jie Yang;Linghong Miao;Juanjuan Dong;F. Song;Z. Dong
本试验旨在研究饲粮中添加胱氨酸（Cys）和酪氨酸（Tyr）对初始体重为15.04 ± 0.03 g的马来西亚红罗非鱼皮肤黑色素生成途径的影响。配制6种实用饲粮，分别在对照饲粮的基础上添加0.1%、0.5%、1%胱氨酸（Cys）和0.5%、1%、2%酪氨酸（Tyr），分别命名为control、Cys-0.1%、Cys-0.5%、Cys-1%、Tyr-0.5%、Tyr-1%和Tyr-2%。试验期间，每种饲料分别饲喂三组鱼。试验结束时，各组末重差异无统计学意义（P> 0.05）。然而，饲料中添加Cys和Tyr对鱼皮肤中黑色素水平和酪氨酸酶活性有显著影响。鱼皮黑色素含量以Cys-0.5%组最低，Cys-0.1%和Cys-1%组较高。Cys-1%组鱼皮最终黑色素含量高于Cys-0.5%和Cys-0.1%组（P< 0.05）。试验结束时，Tyr-2%组鱼腹部皮肤黑色素含量高于Tyr-0.5%和1%组（P< 0.05），Tyr-0.5%组鱼背部皮肤黑色素含量低于Tyr-1%和2%组（P< 0.05）。Cys-1%水平的鱼皮最终酪氨酸酶活性最高，Tyr-1%和Tyr-2%水平的鱼皮最终酪氨酸酶活性显著高于Tyr-0.5%水平（P< 0.05）。血清中酪氨酸酶活性在Cys-1%时最高，且Tyr-2%的酪氨酸酶活性显著高于Tyr-1%和Tyr-0.5% （P< 0.05）。切片显微结构观察，Cys-1%组腹侧皮肤黑色素区最大。酪氨酸-2%组酪氨酸酶mRNA在鱼腹侧皮肤的表达量最高。试验结束时，Cys-0.5%组鱼背皮肤酪氨酸酶mRNA含量最低，Cys-0.1%和Cys-1%组鱼背皮肤酪氨酸酶mRNA含量较高。鱼背皮肤中Tyr-0.5%酪氨酸酶mRNA最终表达量低于Tyr-1%和Tyr-2% （P< 0.05）。鱼背皮肤中，Tyr-1%组slc7a11mrna的最终表达量高于Tyr-0.5%组（P< 0.05）。上述结果表明，饲料中添加Cys和Tyr可影响红罗非鱼黑色素合成途径。
A 68-day experiment was conducted to investigate the effects of dietary cystine (Cys) and tyrosine (Tyr) on skin melanogenesis pathways in Malaysian red tilapia (initial weight: 15.04 ± 0.03 g). Six practical diets containing extra 0.1%, 0.5%, 1% cystine (Cys) and 0.5%, 1%, 2% tyrosine (Tyr) based on the control diet were prepared, accordingly named as Control, Cys-0.1%, Cys-0.5%, Cys-1%, Tyr-0.5%, Tyr-1% and Tyr-2% respectively. Each diet was fed to triplicate groups of fish during the trial. At the end of the experiment, the final weight for each group was not significantly different (P> 0.05). However, the dietary Cys and Tyr had significant effects on the melanin level and tyrosinase activity in the skin of fish. The melanin content in the skin of fish was lowest in Cys-0.5% group, with a higher level observed at Cys-0.1% and Cys-1% group. The final melanin of fish skin in Cys-1% was higher than that in Cys-0.5% and Cys-0.1% (P< 0.05). At the end of the experiment, the melanin in ventral skin of fish in Tyr-2% was higher than that in Tyr-0.5% and Tyr-1% (P< 0.05), and the melanin in dorsal skin of fish in Tyr-0.5% was lower than that in Tyr-1% and Tyr-2% (P< 0.05). The final tyrosinase activity of fish skin in Cys-1% was highest, and the final tyrosinase activity in Tyr-1% and Tyr-2% were significantly higher than that in Tyr-0.5% (P< 0.05). In serum, the tyrosinase activity was highest in Cys-1%, and the tyrosinase activity in Tyr-2% was significantly higher than that in Tyr-1% and Tyr-0.5% (P< 0.05). Moreover, the ventral skin melanin zone in Cys-1% treatment is largest by slice microstructure observation. The expression of tyrosinase mRNA in Tyr-2% group was highest in ventral skin of fish. At the end of the experiment, tyrosinase mRNA in the dorsal skin of fish was lowest in Cys-0.5%, with a higher level observed at Cys-0.1% and Cys-1% group. The final expression of tyrosinase mRNA in Tyr-0.5% was lower than that in Tyr-1% and Tyr-2% in dorsal skin of fish (P< 0.05). The final expressions ofslc7a11mRNA in Tyr-1% was higher than that in Tyr-0.5% in dorsal skin of fish (P< 0.05). Present results demonstrated that dietary Cys and Tyr could affect the melanin synthesis pathway in the red tilapia.