肉骨粉部分替代鱼粉对大菱鲆幼鱼氨基酸应答信号通路的影响

Influence of Fishmeal Replacement with Meat and Bone Meal on Amino Acid Response Signaling Pathway of Juvenile Turbot(Scophthalmus maximus L.)

为研究肉骨粉部分替代鱼粉(添加或不添加晶体氨基酸)对大菱鲆(Scophthalmus maximus L.)幼鱼的氨基酸应答(AAR)信号通路中关键调控因子基因表达量的影响。设计了3种等氮等能的饲料:鱼粉对照组(FM,60%鱼粉),肉骨粉替代组(MBM,肉骨粉替代45%鱼粉蛋白),肉骨粉替代添加晶体必需氨基酸组(MBM+AA,肉骨粉替代45%鱼粉蛋白,添加晶体必需氨基酸至鱼粉组必需氨基酸水平)。实验选取初始体质量(9.01±0.01)g的大菱鲆,分别饱食投喂3种不同的饲料30天,检测肌肉和肠道中AAR信号通路中关键调控因子的基因表达量。研究表明:与FM组相比,MBM组显著提高了大菱鲆幼鱼肌肉中谷氨酰胺合成酶(Asparagine synthesis,ASNS)、转录激活因子3(Activating transcription factor3,ATF3)、转录激活因子4(Activating transcription factor4,ATF4)、CCAAT增强子结合蛋白(CCAAT-enhance binding protein homology protein,CHOP)、发育和DNA损伤应答调节因子1(Regulated in development and DNA damage responses1,REDD1)和真核翻译起始因子4E结合蛋白1(Eukaryotic initiation factor 4Ebinding protein 1,4E-BP1)表达量的峰值。在摄食后2h,MBM+AA组的ASNS、ATF3、ATF4、CHOP、REDD1和4E-BP1表达量峰值与FM组的表达量峰值无显著性差异,却显著低于MBM组的表达量峰值。3个处理组肌肉中酵母转录激活因子2(General control nonderepressible 2,GCN2)的基因表达量无显著性差异。同时,与FM组相比,MBM组显著上调肠道中GCN2、ASNS、ATF4、CHOP和4EBP1表达量的峰值,MBM+AA组对于降低这些基因的表达量无显著性效果。研究结果表明:肉骨粉替代45%鱼粉蛋白上调了肌肉和肠道中AAR信号通路中关键因子的表达,添加晶体氨基酸可以在一定程度上改善肉骨粉替代鱼粉对于肌肉中AAR信号通路中关键调控因子表达量的上调作用。

The objective of this study was to evaluate the effect of fishmeal（FM）replacement with meat and bone meal（MBM）balanced with or without essential aminoacids（EAA）on the amino acid response（AAR）signaling pathway in juvenile turbot,Scophthalmusmaximus L.Fish（9.01±0.01）g were fed with three isonitrogenous and isoenergetic diets including 60% FM（FM diet）;45% FM replaced by MBM diet（MBM diet）and MBM diet supplemented with EAAs to match the EAA profile of FM diet（MBM＋AA diet）for 30 days.Results showed that compared with the FM diet,MBM diet significantly up-regulated the gene expression peak levels of asparagine synthesis（ASNS）,activating transcription factor3（ATF3）,activating transcription factor4（ATF4）,CCAAT-enhance binding proteinhomology protein（CHOP）,regulated in development and DNA damage responses 1（REDD1）and eukaryotic initiation factor 4Ebinding protein 1（4E-BP1）in muscle.There were no difference between the MBM＋AA diet and FM diet on the genes expression level of ASNS,ATF3,ATF4,CHOP,REDD1 and 4E-BP1at2 hafter re-feeding.The MBM＋AA diet and FM diet significantly down-regulated the expression of these genes in comparison with MBM diet.There was no significant difference on the expression of general control nonderepressible 2（GCN2）among the three diets.Similarly,in intestine,MBM diet significantly increased the gene expression peak level of GCN2,ASNS,ATF4,CHOP and 4E-BP1 in comparison with FM diet.Added EAA had no effect to decrease these genes expression level.In conclusion,45% FM replaced by MBM diet up-regulated the gene expression level of the key regulators involved in AAR signaling pathway,and supplemented EAA had an effect to ameliorate MBM replacement deficiency to some extent.