四种不同添加物对仿刺参非特异性免疫力和肠道免疫基因Aj-p105、Aj-p50、Aj-rel和Aj-lys mRNA表达的影响

Effects of four different additives on non-specific immunity and expression of intestinal immune gene( Aj-p105,Aj-p50,Aj-rel and Aj-lys) in sea cucumber( Apostichopus japonicus)

本实验研究了饲料中添加酵母多糖(6.3 g/kg)、马氏副球菌(109cfu/kg)、大黄(25.0 g/kg)和氟苯尼考(15.0 mg/kg)4种添加物对仿刺参[初始体质量(4.68±0.36)g]非特异性免疫力以及肠道组织免疫相关基因Aj-p105、Aj-p50、Aj-rel和Aj-lys mRNA表达的影响。每个处理分别设置5个重复,以投喂未添加上述任何成份的基础饲料组作为空白对照,养殖实验周期为60 d。结果发现,饲料中添加马氏副球菌能显著提高仿刺参体腔细胞的吞噬活性和呼吸爆发活力,而添加酵母多糖可以显著提高仿刺参体腔细胞的吞噬能力,但是添加氟苯尼考显著降低了仿刺参体腔细胞的呼吸爆发活力;而在仿刺参中肠肠道组织中,酵母多糖和马氏副球菌处理组免疫基因Aj-p105和Aj-p50 mRNA的表达均大幅上调,显著高于对照组。其中,酵母多糖添加组增幅分别为43.2%和63.1%,马氏副球菌添加组的增幅分别为49.8%和48.0%。马氏副球菌添加组中免疫基因Aj-lys的表达显著高于对照组,增幅为46.4%;大黄添加组中Aj-p105 mRNA的表达量显著高于对照组,而氟苯尼考添加组中Aj-p50、Aj-rel和Aj-lys的mRNA表达量相对于对照组均显著下降。研究表明,饲料中适当添加酵母多糖和马氏副球菌可有效提高仿刺参非特异性免疫力,而饲料中抗生素氟苯尼考的添加会降低仿刺参非特异性免疫力。

A 60-d feeding experiment was conducted to investigate the effects of basic diet with four different additives of yeast polysaccharide（ 6. 3 g / kg）,Paracoccus marcusii（ 109 cfu / kg）,rhubarb（ Rhei Radix et Rhizoma,25. 0 g / kg） and florfenicol（ 15. 0 mg / kg） on non-specific immunity and expression of intestinal immune gene（ Aj-p105,Aj-p50,Aj-rel and Aj-lys） in sea cucumber[Apostichopus japonicus,mean initial body weight（ 4. 68 ± 0. 36） g]. Five groups of sea cucumbers were fed with the basal diet（ control group）,basal diet with yeast polysaccharide,P. marcusii,rhubarb,and florfenicol supplementation,respectively. Each diet was randomly fed to five tanks at a density of 10 sea cucumbers per tank. The results show ed that the phagocytosis and respiratory burst activities of the coelomocytes of sea cucumber fed diets with P. marcusii supplementation were significantly higher than those in the control group. Dietary yeast polysaccharide supplementation significantly enhanced the phagocytosis activity of the coelomocytes compared with the control group. How ever,the respiratory burst activity of the coelomocytes in the florfenicol group was significantly low er than that in the control group. At transcriptional level,the relative expression of Aj-p105 and Aj-p50 genes in mid-intestine tissue of sea cucumber in yeast polysaccharide and P. marcusii groups were significantly higher than those in the control group with increase of 43. 2% and63. 1% in yeast polysaccharide group,and with increase of 49. 8% and 48% in P. marcusii group,respectively. The relative expression of Aj-lys gene in P. marcusii group was significantly higher than that in the control group with an increase of 46. 4%. The relative expression of Aj-p105 in rhubarb group was significantly higher than that in the control group. While the expression of Aj-p50,Aj-rel and Aj-lys genes in mid-intestine of sea cucumber in florfenicol group was significantly decreased compared to the control group. In summary,these results suggested that dietary yeast polysaccharide and P. marcusii w ould enhance the non-specific immunity of sea cucumber,but feeding florfenicol may have an opposite effect.