育肥饲料中植物油混合替代鱼油对中华绒螯蟹雄体脂肪酸代谢相关基因表达的影响

为研究植物油替代鱼油对中华绒螯蟹(以下简称河蟹)脂肪酸代谢产生的影响, 通过荧光定量PCR (qRTPCR)技术研究了河蟹脂肪酸碳链延长酶(Es-FAE)、9脂肪酸去饱和酶(Es-FAD9)、6脂肪酸去饱和酶b (Es-FAD6b)、脂肪酸结合蛋白3 (Es-FABP3)、脂肪酸结合蛋白9 (Es-FABP9)和脂肪酸结合蛋白10 (Es-FABP10)基因在不同组织中的表达情况, 以及育肥饲料中不同鱼油替代水平(鱼油替代水平分别为0、25%、50%、75%和100%, 记为饲料1#5#组)对河蟹雄体肝胰腺中这些基因mRNA表达水平的影响, 以探讨育肥中鱼油替代对河蟹雄体成蟹脂肪酸代谢的影响。结果表明: (1) Es-FAE、Es-FAD6b和Es-FAD9均在肝胰腺中表达水平最高, 在心脏和血淋巴中表达水平较低, 不同基因在其他组织中的表达规律有所不同; Es-FABP3、Es-FABP9和Es-FABP10主要在肝胰腺、肌肉、输精管和副性腺中表达水平较高, 在胃、肠和心脏中表达水平较低。(2) 随着饲料中鱼油替代水平的提高, 肝胰腺中Es-FAE-mRNA有显著增加趋势; 就Es-FAD6b而言, 饲料3#组显著高于饲料2#组, 其余各组间差异不显著; 随着饲料中鱼油水平的降低, 饲料1#3#组肝胰腺中Es-FAD9-mRNA也有显著增加趋势, 但差异不显著。(3) 就Es-FABP3而言, 饲料2#和3#组肝胰腺中表达水平最高,且显著高于饲料1#组(P0.05), 其余各组间差异不显著; 随着鱼油替代水平的升高, 肝胰腺中Es-FABP9和Es-FABP10-mRNA水平均有先上升后下降趋势, 但各组间差异不显著。综上, 河蟹脂肪酸代谢和转运相关基因在肝胰腺中表达水平最高, 饲料中不同鱼油替代水平对肝胰腺中上述基因mRNA表达水平具有较大影响。

EFFECTS OF FISH OIL REPLACEMENT BY VEGETABLE OILS IN FATTENING DIETS ON THE RELATED GENE EXPRESSION OF FATTY ACID METABOLISM OF ADULT MALE CHINESE MITTEN CRAB,ERIOCHEIRSINENSIS

Fish oil is one of the major aquafeed ingredients, however, the world fish oil production could not meet the demand of global aquafeed industry. Thus, fish oil replacement have became a hot topic for the research and develop-ment of aquaculture. Chinese mitten crab Eriocheir sinensis is an important aquaculture species in China, and the pre-vious study has shown the dietary substitution of fish oil with vegetable oil negatively impact the gonadal development and nutritional quality of this species possibly via lipid metabolism. The present study investigated the expression pat-tern of fatty acid metabolism-related genes, including fatty acyl elongase (Es-FAE),Δ9 fatty acyl desaturase (Es-FAD9),Δ6 fatty acyl desaturase (Es-FAD6b), fatty acid-binding protein 3 (Es-FABP3), fatty acid-binding protein 9 (Es-FABP9) and fatty acid-binding protein 10 (Es-FABP10), and their expression by different fish oil replacement levels (i.e. 0, 25%, 50%, 75%and 100%) in the hepatopancreas of E. sinensis. The results indicated that Es-FAE, Es-FAD9 and Es-FAD6b had the highest expression levels in hepatopancreas but low expression levels in heart and haemo-lymph, and that Es-FABP3, Es-FABP9 and Es-FABP10 were mainly distributed in hepatopancreas, muscle, seminal and accessory gland whereas the relatively low expression levels in stomach, intestine and heart. The Es-FAE-mRNA ex-pression level in hepatopancreas significantly increased with the increasing dietary fish oil replacement levels. Diet 2# treatment had significantly higher Es-FAD6b-mRNA expression level than the Diet 3# treatment but no significant dif-ference among other treatments. Decreasing dietary fish oil contents reduced the expression of the Es-FAD9 in hepato-pancreas but without significant difference. (3) Diet 2# and Diet 3# but not other treatments significantly induced Es-FABP3-mRNA expression in hepatopancreas (P<0.05). Dietary fish oil replacement did not significantly regulate Es-FABP9 and Es-FABP10-mRNA expression but had trend of‘low-high-low’ in the hepatopancreas among the five treat-ments. These results indicated that hepatopancreas had the highest mRNA expression of the genes related to fatty acid metabolism and transportation, and that dietary fish oil replacement had significant effects on their expression.