配合饲料、冰鲜杂鱼对大口黑鲈生长和LPL基因mRNA表达的影响

以体质量为40 g的大口黑鲈Micropterus salmoides为试验对象，分别投喂冰鲜杂鱼（对照）、 A配合饲料（脂肪含量8.2%）和B配合饲料（脂肪含量14.5%），饲养试验共进行3个月，试验结束时测量各组鱼的生长性状，并检测其肝脏中两种脂蛋白脂肪酶基因LPLtype1和LPLtype2 mRNA的表达量。结果表明：喂食冰鲜杂鱼的大口黑鲈平均体质量增加率显著高于喂食两种配合饲料的大口黑鲈（ P〈0.05）；喂食B配合饲料的大口黑鲈肝脏中LPLtype1和LPLtype2 mRNA的相对表达量与对照组、喂食A配合饲料的组存在显著性差异（P〈0.05），饲料脂肪水平越高， LPLtype1和LPLtype2 mRNA的表达量也越高。研究表明，脂蛋白脂肪酶LPLtype1和 LPLtype2基因编码的蛋白都具有分解贮存在肝脏细胞中多余脂肪的功能，且LPLtype2与LPLtype1基因可能存在更加精细的分工， LPLtype2比LPLtype1更易受饲料脂肪含量的调节，推测LPLtype2在参与分解肝细胞的脂肪中可能起到更大的作用。

Effects of formulated diets and frozen trash fish on growth and expression of LPL gene mRNA in largemouth bass Micropterus salmoides

Largemouth bass Micropterus salmoides with mean body weight of 40 g were fed frozen fresh fish （ as con-trol）, formulated diet A （fat level 8. 2%） and formulated diet B （fat level 14. 5%） for 3 months, and mRNA ex-pression levels of two lipoprotein lipases （LPL）, LPLtype1 and LPLtype2, were detected in livers of the largemouth bass. The results showed that there was significantly higher average body weight gain in the fish fed the frozen trash fish than the fish fed formulated diet A and formulated diet B （ P〈0 . 05 ） . The fish fed formulated diet B had signif-icant differences in hepatic expression levels of LPLtype1 and LPLtype 2 mRNA from the largemouth bass fed for-mulated diet A and the fish fed the frozen fresh fish （ P〈0 . 05 ） , with the higher expression levels of LPLtype1 and LPLtype2 mRNA in the fish fed the higher dietary fat level. The findings indicate that LPLs play an important role in hydrolysis of the extra fat in hepato cytes. There are more precise function divisions between LPLtype1 and LPL-type 2 genes, and LPLtype 2 is more susceptible to dietary fat concentration than LPLtype 1 does, showing more important function in lipoprotein metabolism hepatocytes.