目的探讨黄曲霉(A.flavus)基因敲除体系的构建和RNA依赖的RNA聚合酶1(RDRP1)基因在A.flavus生长发育中的作用。方法通过National Center for Biotechnology Information网址查找RDRP1基因,设计上下游序列引物,引入融合片段20 bp,采用重...目的探讨黄曲霉(A.flavus)基因敲除体系的构建和RNA依赖的RNA聚合酶1(RDRP1)基因在A.flavus生长发育中的作用。方法通过National Center for Biotechnology Information网址查找RDRP1基因,设计上下游序列引物,引入融合片段20 bp,采用重叠PCR(overlap PCR)法融合RDRP1基因上下游片段和嘧啶磺胺抗性基因(ptrA);采用聚乙二醇(PEG)介导方法将该融合片段导入A.flavus的原生质体中获得RDRP1阳性转化子(ptrA抗性),采用Sourthern blot鉴定筛选RDRP1基因突变菌株;对RDRP1基因突变菌株,采用十字交叉法测定生长速率、血细胞计数板统计产孢量,手动计数Wickerham Medium(WKM)+尿嘧啶尿苷(UU)培养基上产生的菌核数量。结果获得ptrA抗性转化子13个;Sourthern blot鉴定4个为RDRP1基因缺失菌株,效率30.8%;与CA14相比,RDRP1基因突变菌株在表型、生长率、产孢量及菌核发育上差异无统计学意义(P>0.05)。结论overlap PCR结合PEG介导转化的方式可短时间内获得A.flavus基因敲除突变菌株,RDRP1基因不参与A.flavus表型、生长率、产孢量及菌核发育的调控作用。展开更多
NADP(H) dependent retinol dehydrogenase/reductase (NRDR) was an important retinoic acid synthase, which was first purified from rabbit liver in 1997. In order to study the function of the NRDR gene,the full length cDN...NADP(H) dependent retinol dehydrogenase/reductase (NRDR) was an important retinoic acid synthase, which was first purified from rabbit liver in 1997. In order to study the function of the NRDR gene,the full length cDNA of bovine NRDR was cloned. According to the conserved sequences of human, mouse and rabbit NRDR cDNA, a pair of primers was designed to amplify a 294 bp DNA fragment of bovine liver NRDR, and then the full length of NRDR cDNA (AF487454) was cloned by using 3′ RACE and 5′ RACE. All the cloned NRDR proteins consist of 260 amino acid residues and showed high identity among them. The tri peptide of human, mouse and rabbit NRDR C end was SRL and that of bovine NRDR C end was SHL, but both were considered to be peroxisomal target signal 1 (PTS1). RT PCR demonstrated that NRDR gene was expressed in liver, heart, lung, kidney, stomach and intestine, and was not found in pancreas, muscle, artery and skin. The full length bovine NRDR cDNA has been successfully cloned and the sequence was analyzed. It provided a reliable foundation to investigate the biological function of this protein.展开更多
文摘NADP(H) dependent retinol dehydrogenase/reductase (NRDR) was an important retinoic acid synthase, which was first purified from rabbit liver in 1997. In order to study the function of the NRDR gene,the full length cDNA of bovine NRDR was cloned. According to the conserved sequences of human, mouse and rabbit NRDR cDNA, a pair of primers was designed to amplify a 294 bp DNA fragment of bovine liver NRDR, and then the full length of NRDR cDNA (AF487454) was cloned by using 3′ RACE and 5′ RACE. All the cloned NRDR proteins consist of 260 amino acid residues and showed high identity among them. The tri peptide of human, mouse and rabbit NRDR C end was SRL and that of bovine NRDR C end was SHL, but both were considered to be peroxisomal target signal 1 (PTS1). RT PCR demonstrated that NRDR gene was expressed in liver, heart, lung, kidney, stomach and intestine, and was not found in pancreas, muscle, artery and skin. The full length bovine NRDR cDNA has been successfully cloned and the sequence was analyzed. It provided a reliable foundation to investigate the biological function of this protein.
