Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Fish Shellfish Immunol. 2017 Nov;70:621-627. doi: 10.1016/j.fsi.2017.09.048. Epub 2017 Sep 19.
Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is an important economical shrimp species worldwide, especially in the Middle East region, and farming activities of this species have been largely affected by diseases, mostly viral and bacterial diseases. Scientists have started to use prebiotics for bolstering the immune status of the animal. This study aimed to investigate the influence of Immunogen on growth, digestive enzyme activity and immune related gene expression of Litopenaeus vannamei post-larvae. All post-larvae were acclimated to the laboratory condition for 14 days. Upon acclimation, shrimps were fed on different levels of Immunogen (0, 0.5, 1 and 1.5 g kg) for 60 days. No significant differences were detected in weight gain, specific growth rate (SGR) and food conversion ratio (FCR) in shrimp post-larvae in which fed with different levels of Immunogen and control diet. The results showed that digestive enzymes activity including protease and lipase increased with different amounts of Immunogen in the shrimp diet. Protease activity increased with 1.5 g kg Immunogen after 60 days and lipase activity increased with 1 and 1.5 g kg Immunogen after 30 and 60 days of the trial respectively (P < 0.05), while amylase activity did not change in response to different levels of Immunogen (P > 0.05). The expression of immune related genes including, prophenoloxidase, crustin and g-type lysozyme increased with diet 1.5 g kg Immunogen (P < 0.05) while expression of penaeidin gene increased only with experimental diet 1 g kg of Immunogen. These results indicated that increase in digestive enzymes activity and expression of immune related genes could modulate the Immunogen in the innate immune system in L. vannamei in this study.
太平洋白对虾 Litopenaeus vannamei (Boone, 1931) 是世界范围内一种重要的经济虾类，尤其在中东地区，该物种的养殖活动受到了多种疾病的严重影响，主要是病毒性和细菌性疾病。科学家们已经开始使用益生元来增强动物的免疫状态。本研究旨在探讨免疫原对凡纳滨对虾幼虾生长、消化酶活性和免疫相关基因表达的影响。所有幼虾均在实验室条件下适应 14 天。适应后，虾用不同水平的免疫原（0、0.5、1 和 1.5 g/kg）喂养 60 天。在不同水平的免疫原和对照饲料喂养的幼虾中，体重增加、特定生长率（SGR）和饲料转化率（FCR）没有显著差异。结果表明，在虾饲料中添加不同量的免疫原可提高蛋白酶和脂肪酶等消化酶的活性。蛋白酶活性在 60 天后随 1.5 g/kg 免疫原的增加而增加，脂肪酶活性在 30 和 60 天后随 1 和 1.5 g/kg 免疫原的增加而增加（P<0.05），而淀粉酶活性对不同水平的免疫原没有变化（P>0.05）。免疫相关基因如酚氧化酶原、壳聚糖和 g 型溶菌酶的表达随饲料中 1.5 g/kg 免疫原的增加而增加（P<0.05），而抗菌肽基因的表达仅随 1 g/kg 实验饲料的免疫原增加。这些结果表明，在本研究中，消化酶活性和免疫相关基因的表达增加可能会调节 L. vannamei 先天免疫系统中的免疫原。
