论文部分内容阅读
分离、克隆了吉富罗非鱼脂肪酸合成酶(fatty acid synthase,FAS)基因的部分cDNA片段,共557bp,编码185个氨基酸,序列分析表明吉富罗非鱼FAS与其他物种的相似性为62%～82%。为了研究饲料中脂肪对吉富罗非鱼FAS活性和表达的影响,设置3组含不同脂肪含量的等氮饲料组(3.71%组、7.67%组和16.55%组),饲养90d,禁食48h,测定吉富罗非鱼肝脏中FAS的生物活性,使用实时荧光定量PCR分别测定了饲喂3.71%组、7.67%组和16.55%组饲料的吉富罗非鱼肝脏和肌肉中FASmRNA的表达丰度以及再投喂后6、12、24、48h肝脏中FASmRNA的表达丰度。结果显示,饲料脂肪水平对肝脏中FAS活性无显著影响(P>0.05);肝脏中FASmRNA的表达丰度显著高于肌肉(P<0.05),肝脏和肌肉中FASmRNA的表达丰度随着饲料中脂肪水平增加而显著下降(P<0.05);再次投喂后6～48h,各个组的肝脏中FASmRNA表达丰度显著下降(P<0.05)。结果说明,吉富罗非鱼肝脏中FASmRNA的表达丰度高于肌肉,饲料脂肪水平能够抑制FASmRNA表达,脂肪水平越高抑制作用越明显,再投饲后6～48h,FAS基因的表达受到抑制。
A partial cDNA fragment of FAS gene was isolated and cloned, a total of 557bp, encoding a protein of 185 amino acids. The sequence analysis showed that the similarity of FAS among other species was 62% 82%. In order to study the effect of dietary fat on the FAS activity and expression in tilapia, three groups of isosilate with different fat content (3.71% The bioactivity of FAS in the liver of GIFT tilapia was determined and the expression abundance of FAS mRNA in liver and muscle of GIFT tilapia fed with diet of 3.71%, 7.67% and 16.55% were measured by real-time fluorescence quantitative PCR, The expression abundance of FAS mRNA in the liver at 6, 12, 24, 48 h after feeding. The results showed that the dietary fat level had no significant effect on the FAS activity in the liver (P> 0.05). The abundance of FAS mRNA expression in the liver was significantly higher than that in the muscle (P <0.05) (P <0.05). The abundance of FAS mRNA in each group decreased significantly (P <0.05) at 6 ~ 48h after re-feeding. The results showed that the abundance of FAS mRNA expression in the liver was higher than that in the muscle. The feed fat level could inhibit the expression of FAS mRNA. The higher the fat level, the more obvious the inhibitory effect was, and the FAS gene expression was inhibited 6 ~ 48 h after re-feeding.