饲料中维生素D3水平对黄鳝抗菌肽hepcidin基因表达的影响

本试验旨在探索饲料中维生素D3水平对黄鳝(Monopterus albus)抗菌肽hepcidin基因表达的影响.挑选体质健康、平均体重为(21.7±2.1)g的黄鳝360尾,随机分为6组,每组2个重复,每个重复30尾.6组黄鳝分别饲喂在基础饲料(0 IU/kg维生素D3)中添加0、250、500、1 000、2 000和4 000 IU/kg维生素D3的试验饲料.于投喂试验饲料后20、40和60 d,从各组随机选择6尾黄鳝,分别采集其肝胰脏、脾脏、头肾和后肠组织,采用荧光定量聚合酶链式反应(RT-PCR)技术检测样品中hepcidin基因表达量.结果表明:投喂20、40和60 d后,黄鳝4种组织中均有hepcidin基因表达,并且肝胰脏中显著高于脾脏、头肾和后肠中(P＜0.05)；随维生素D3添加水平的增加,黄鳝hepcidin基因在4种组织的表达量同一时间点均呈现出先升高后降低的趋势；第20天时4种组织中的表达量均以2 000 IU/kg组为最高,显著高于其他各组(P＜0.05)；第40和60天时肝胰脏、头肾中的表达量均以500 IU/kg组为最高,其中第40天时显著高于0、250、4 000 IU/kg组(P＜0.05),第60天时显著高于其他各组(P＜0.05).结果提示,短期(20 d)内在饲料中添加2 000 IU/kg的维生素D3可显著提高黄鳝内脏组织中hepcidin 基因的表达量；饲喂周期较长(40或60 d)时,饲料中添加500 IU/kg维生素D3可显著提高hepcidin基因在黄鳝肝胰脏和头肾中的表达量.

Effects of Dietary Vitamin D3 Level on Expression of Antimicrobial Peptide hepcidin Gene in Monopterus albus

This experiment was conducted to study the effects of dietary vitamin D3 level on expression of antimicrobial peptide hepcidin gene in Monopterus albus.A total of 360 healthy M.albus with an average body weight of(21.72±2.1) g was randomly assigned to 6 groups with 2 replicates per group and 30 M.albus per replicate.The M.albus in the 6 groups were fed the basal diet(0 IU/kg vitamin D3) supplemented with 0,250,500,1 000,2 000 and 4 000 IU/kg vitamin D3,respectively.The hepatopancreas,head kidney,spleen and hindgut in each group were collected on the 20th,40th and 60th days.The expression of hepcidin gene in each sample were analyzed using real-time PCR.Results showed as follows: after feeding 20,40 and 60 days,the hepcidin gene had expressed in 4 tissues of M.albus,and that in hepatopancreas was higher than that in head kidney,spleen and hindgut(P<0.05).At the same feeding stage,with increasing vitamin D3 supplemental level,the expression of hepcidin gene in 4 tissues was firstly increased and then decreased.On the 20th day,the highest values of hepcidin gene expression in 4 tissues were all found in 2 000 IU/kg group,and there were significant differences between 2 000 IU/kg group and other groups(P<0.05).On the 40th and 60th days,the highest values of hepcidin gene expression in hepatopancreas and head kidney were all found in 500 IU/kg group,and there were significant differences between 500 IU/kg group and 0,250,4 000 IU/kg groups on the 40th day(P<0.05),and between 500 IU/kg group and other groups on the 60th day(P<0.05).In conclusion,in a short time(20 days) feeding,supplementation of 2 000 IU/kg vitamin D3 can significantly promote the hepcidin gene expression in splanchnic tissues of M.albus;in a long time(40 or 60 days) feeding,supplementation of 500 IU/kg vitamin D3 can significantly promote the hepcidin gene expression in hepatopancreas and head kidney of M.albus.