分泌表达pEGF的重组酿酒酵母在断奶仔猪上的应用研究

Application Research of Recombinant EGF-expressed Saccharomyces cerevisiae in Early-weaned Piglets

本研究对分泌表达pEGF的重组酿酒酵母在断奶仔猪日粮中的应用效果进行验证。72头21~24日龄的断奶仔猪((6.10±0.15)kg),随机分为3组(每组4个重复,每个重复6头):对照组(基础日粮+228mL·kg^(-1)空白培养液)、空载体组(基础日粮+228mL·kg^(-1)空载体)及重组酵母组(基础日粮+228mL·kg^(-1) INVSc1(pYES2-Mfα-spEGF))。21d后,每组每栏选取1头仔猪屠宰,分别测定其小肠组织形态、小肠黏膜中IgA、IgG及IgM水平,碱性磷酸酶(ALP)、肌酸激酶(CK)及乳酸脱氢酶(LDH)的酶活力及mRNA转录水平,小肠黏膜中表皮生长因子受体(Epidermal growth factor receptor,EGF-R)的mRNA转录水平。结果表明,与对照组及空载体组相比,重组酵母组INVSc1(pYES2-Mfα-spEGF)能够显著提高断奶仔猪小肠各段(十二指肠、空肠及回肠)黏膜中EGF-R及消化酶(ALP、CK及LDH)的mRNA转录水平(P<0.05),极显著提高CK和LDH的酶活力(P<0.01),显著促进其空肠及回肠黏膜中IgA、IgG及IgM水平(P<0.05),提高其平均日增重(ADG)及降低F/G(P<0.05)。综上,本研究获得的重组酿酒酵母INVSc1(pYES2-Mfα-spEGF)表达的EGF蛋白具有较高的生物学活性,能明显促进断奶仔猪小肠黏膜发育及其免疫功能,具有向养猪生产进一步转化的开发价值。

The application research of recombinant pEGF-expressed S. cerevisiae in early-weaned piglets was verified in the present research. A total of 72 piglets （body weight was （6.10±0.15） kg） weaned at 21-24 day of age were randomly assigned to 3 groups （4 replicates in each group, 6 per replicate） .control group （basal diet＋228 mL · kg 1 culture medium） ,empty vector-expressed S. cerevisiae group （basal diet＋228 mL · kg-1 INVScl（EV））,and recombinant EGF-expressed S. cerevisiae group （basal diet＋228 mL · kg 1 INVScl （pYES2-Mf-spEGF））. At day 21, onepiglet from each pen were randomly chosen to be killed to investigate the morphology, the levels of IgA,IgG and IgM, the enzyme activities and mRNA expression levels of ALP, CK and LDH, and the mRNA expression of EGF-R in the intestinal mucosa. As shown in this study,the mRNA expression levels of digestive enzymes （ALP,CK and LDH） and EGF-R （P〈0. 05）, the activi- ties of CK and LDH （P〈0. 01）,the levels of IgA,IgG and IgM （P〈0. 05）,the ADG （P〈0.05） were significantly increased, and F/G（P〈0. 05） was significantly decreased in the recombinant pEGF-expressed S. cerevisiae group compared with the control and INVScl（EV） groups. Herein, recombinant pEGF-expressed S. cerevisiae in this study have higher biological activities,including im- proving intestinal development and immune function,which will be applied in the swine industry.