蜈蚣藻多糖对凡纳滨对虾免疫相关基因表达的影响

Effects of Grateloupia filicina polysaccharide on immune-related gene expression in Litopenaeus vannamei

【目的】研究蜈蚣藻多糖对凡纳滨对虾免疫相关基因表达的影响,为今后将蜈蚣藻多糖开发成凡纳滨对虾免疫增强剂提供理论依据。【方法】将试验凡纳滨对虾随机分为4组,其中A组(对照组)对虾投喂基础饵料,B、C、D组对虾分别喂食含有0.1%、0.2%和0.3%蜈蚣藻多糖的药饵,饲养15 d后采用实时定量PCR对各组凡纳滨对虾的肝胰腺组织真核细胞翻译起始因子5A、巨噬细胞移动抑制因子、血蓝蛋白、酚氧化酶原、C凝集素、溶菌酶、热休克蛋白70等7个免疫相关基因的表达水平进行检测。【结果】投喂基础饵料和投喂蜈蚣藻多糖药饵的凡纳滨对虾在外表和行为上无明显差别,且均未出现对虾死亡现象。与A组相比,B、C、D组对虾肝胰腺组织中血蓝蛋白、酚氧化酶原、热休克蛋白70等3个基因的表达量明显升高,且均表现为D组>C组>B组>A组;而真核细胞翻译起始因子5A、巨噬细胞移动抑制因子、C凝集素、溶菌酶等4个基因的表达量无明显变化。【结论】蜈蚣藻多糖可影响凡纳滨对虾的非特异性免疫功能,今后可将蜈蚣藻多糖用于对虾病害防治,以减少化学药物的使用。

[Objective]The effects of Grateloupia filicina polysaccharide on immune-related gene expression in Litope- naeus vannamei were studied to provide theoretical references for developing Grateloupia filicina polysaccharide as Litope- naeus vannamei immunopotentiator. [Method]Litopenaeus vannamei was randomly divided into four groups. The shrimps in group A as control were fed with a basal diet, and the shrimps in group B, C and D were fed with diets containing 0.1%, 0.2% and 0.3% Grateloupia filicina polysaccharide, respectively. After 15 d feeding, the expression levels of seven immune-related genes, including eukaryotic translation initiation factor 5A, macrophage migration inhibitory factor, hemocyanin, prophe- noloxidase, C-type lectin, lysozyme, and heat shock protein 70, in hepatopancreas tissues of each group were detected using real-time quantitative PCR. [Result]The appearance and behavior of Litopenaeus vannamei fed with a basal diet and with Gratelonpia filicina polysaccharide were similar and no death occurred. The results showed that compared with the control group （group A）, the expression levels of hemocyanin, prophenoloxidase, and heat shock protein 70 significantly increased in the treatment groups （D〉C〉B〉A）. No obvious change happened to eukaryotic translation initiation factor 5A, macrophage mi- gration inhibitory factor, C-type lectin or lysozyme. [Conclusion]The results indicated that adding Grateloupia filicina polysaccharide into the diets can significantly improve Litopenaeus vannamei immune function, thus it can replace chemical drugs for disease prevention of Litopenaeus vannamei.