College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
Fisheries Research Institute of Sichuan Academy of Agricultural Sciences, Yibin, 644000, China.
Fish Shellfish Immunol. 2019 Nov;94:199-210. doi: 10.1016/j.fsi.2019.09.012. Epub 2019 Sep 6.
The poor understanding of nutrition needed has become a significant obstruction to artificial conservation of Yangtze sturgeon (Acipenser dabryanus) and the relationship between ployunsaturated fatty acid nutrition and the immune response of Yangtze sturgeon is remains unclear. To explore this relationship, the immune response was determined by the activities of serum immune-related enzymes and the transcriptome pattern in the spleen after feeding different fat source diets for 7 weeks. In addition, the gene expression pattern after a lipopolysaccharide (LPS) challenge was investigated in the presence of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Long-term feeding of the fish oil diets increased the serum immune-related enzyme activities, including lysozyme, acid phosphatase, and alkaline phosphatase of Yangtze sturgeon. More than 653,999 transcripts with an N50 length of 1047 bp were obtained and a final set of 280,408 unigenes was generated. After annotating the unigenes, 3549 genes were assigned to the immune system and 2839 were identified to participate in the response to the different fat sources. A transcriptome assay showed the fish oil diets moderately upregulated immune-related signaling pathways in the spleen of Yangtze sturgeon, including NLR signaling, platelet activation, Fc gamma R-mediated phagocytosis, Th17 cell differentiation, and Th1 and Th2 cell differentiation. The quantitative polymerase chain reaction (qPCR) results of candidate genes for these pathways showed similar results. The LPS challenge study revealed that DHA and EPA moderately upregulated the candidate immune-related genes and modulated excessive activation of the immune pathway by the pathogen. This study confirmed the immunomodulatory function of unsaturated fatty acids in Yangtze sturgeon. This research will provide a reference for the preparation of artificial diets for Yangtze sturgeon.
对营养需求的理解不足已成为人工保护长江鲟（Acipenser dabryanus）的重大障碍，多不饱和脂肪酸营养与长江鲟免疫反应之间的关系仍不清楚。为了探讨这种关系，本研究通过测定不同脂肪源日粮饲养 7 周后血清免疫相关酶活性和脾脏转录组模式来确定免疫反应。此外，还研究了在添加二十二碳六烯酸（DHA）和二十碳五烯酸（EPA）的情况下，脂多糖（LPS）刺激后基因的表达模式。长期喂养鱼油日粮会增加长江鲟血清免疫相关酶的活性，包括溶菌酶、酸性磷酸酶和碱性磷酸酶。获得了超过 653999 个 N50 长度为 1047bp 的转录本，并生成了最终的 280408 个 unigenes 集。对 unigenes 进行注释后，将 3549 个基因分配到免疫系统中，2839 个基因被鉴定为参与对不同脂肪源的反应。转录组分析表明，鱼油日粮适度地上调了长江鲟脾脏中的免疫相关信号通路，包括 NLR 信号、血小板激活、FcγR 介导的吞噬作用、Th17 细胞分化以及 Th1 和 Th2 细胞分化。这些通路的候选基因的定量聚合酶链反应（qPCR）结果显示出相似的结果。LPS 挑战研究表明，DHA 和 EPA 适度地上调了候选免疫相关基因，并调节了病原体对免疫途径的过度激活。本研究证实了不饱和脂肪酸对长江鲟的免疫调节功能。本研究为长江鲟人工饲料的制备提供了参考。
