Wei Banghong, Yang Zhigang, Cheng Yongxu, Wang Jianyi, Zhou Junyu
1Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306 China.
2Centre for Research on Environmental Ecology and Fish Nutrition (CREEFN) of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306 China.
Proteome Sci. 2018 Mar 15;16:6. doi: 10.1186/s12953-018-0135-7. eCollection 2018.
The finite marine resources make it difficult for us to obtain enough fish oil (FO) used in aquatic feeds. Another sustainable ingredients should be found to substitute FO. The effects of replacing FO with vegetable oil have been studied in a variety of crustaceans, but most studies have focused on the phenotypic effects. Little is known about the mechanisms of the effects.
To understand the molecular responses during the replacement of FO in , we investigated the effects of feeding FO or linseed oil (LO) on growth performance, digestive enzyme activity, fatty acid composition and protein expression in . Twenty-four juvenile crabs were fed diets containing FO or LO for 112 days. Weight, carapace length and width were recorded. Fatty acid composition of the diets and the hepatopancreas and protein expression in the hepatopancreas were analyzed.
Growth performance and molting interval were unchanged by diet. Crabs fed FO and LO had same activity of lipase and amylase, but comparing with crabs fed LO, crabs fed FO had higher trypsin activity and lower pepsin activity. Hepatopancreas fatty acid composition changed to reflect the fatty acid composition of the diets. In total, 194 proteins were differentially expressed in the hepatopancreas between the diets. Expression of heat shock proteins was higher in crabs fed LO. Expression of fatty acid synthase, long-chain fatty acid transport protein 4, acyl-CoA delta-9 desaturase, and fatty acid-binding protein 1, was higher in crabs fed FO.
The substitution of FO with LO didn't have any effects on the growth and molting of mitten crab, but could significantly decrease the ability of mitten crab to cope with stress. The high content of HUFAs in the hepatopancreas of mitten crab fed FO is due to the high abundance of the proteins relative to the transport of the HUFAs. These findings provide a reason of the high content of EPA and DHA in crabs fed with FO, and provide new information for the replacement of FO in diets of mitten crab.
有限的海洋资源使我们难以获取足够用于水产饲料的鱼油（FO）。应寻找另一种可持续的成分来替代鱼油。在多种甲壳类动物中已研究了用植物油替代鱼油的效果，但大多数研究都集中在表型效应上。对其作用机制知之甚少。
为了解中华绒螯蟹替代鱼油过程中的分子反应，我们研究了投喂鱼油或亚麻籽油（LO）对中华绒螯蟹生长性能、消化酶活性、脂肪酸组成和蛋白质表达的影响。将24只幼蟹投喂含鱼油或亚麻籽油的饲料112天。记录体重、背甲长度和宽度。分析饲料、肝胰腺的脂肪酸组成以及肝胰腺中的蛋白质表达。
饲料对生长性能和蜕壳间隔没有影响。投喂鱼油和亚麻籽油的螃蟹脂肪酶和淀粉酶活性相同，但与投喂亚麻籽油的螃蟹相比，投喂鱼油的螃蟹胰蛋白酶活性较高，胃蛋白酶活性较低。肝胰腺脂肪酸组成发生变化以反映饲料的脂肪酸组成。两种饲料组之间，肝胰腺中共有194种蛋白质差异表达。投喂亚麻籽油的螃蟹中热休克蛋白的表达较高。脂肪酸合酶、长链脂肪酸转运蛋白4、酰基辅酶Aδ-9去饱和酶和脂肪酸结合蛋白1的表达在投喂鱼油的螃蟹中较高。
用亚麻籽油替代鱼油对中华绒螯蟹的生长和蜕壳没有任何影响，但会显著降低中华绒螯蟹应对压力的能力。投喂鱼油的中华绒螯蟹肝胰腺中高不饱和脂肪酸（HUFA）含量高是由于与HUFA转运相关的蛋白质丰度高。这些发现解释了投喂鱼油的螃蟹中二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）含量高的原因，并为中华绒螯蟹饲料中鱼油的替代提供了新信息。
