The current study describes the molecular characterization of a clone which can restore the ability of bdh A mutant strains NGRPA2 and Rm11107 to utilize 3-hydroxybutyrate as a sole carbon source (Hbu+ ). This clone w...The current study describes the molecular characterization of a clone which can restore the ability of bdh A mutant strains NGRPA2 and Rm11107 to utilize 3-hydroxybutyrate as a sole carbon source (Hbu+ ). This clone was screened out by complementation experiment from Bradyrhizobium japonicum US-DAI 10 genomic library, and the presence of bdhA gene in the clone was verified by Bdh assay and Southern blot analysis. Furthermore, the entire sequence of bdhA. gene was sequenced and the sequence was deposited in GenBank database under the accession number AY077581. bdhA gene comprises 789 base pairs and encodes Bdh with 262 amino acid of MW 27.59 kDa. Interposon JlKm was inserted into the bdhA ORF at EcoR I site and the bdhA mutant was constructed in B .japonicum by homologous recombination. Plant assay result did not show obvious effects of mutation of bdhA gene on nodulation and nitrogen-fixation.展开更多
This paper will correct some gaps existing in the proof of a theorem written in an earlier paper by the author on the lower bounds for sums of BDH type published in 1993. Some improvements upon the previous version of...This paper will correct some gaps existing in the proof of a theorem written in an earlier paper by the author on the lower bounds for sums of BDH type published in 1993. Some improvements upon the previous version of that theorem will be obtained.展开更多
目的探讨β-羟丁酸脱氢酶2(BDH2)基因对肝癌细胞增殖能力的抑制作用及其机制。方法合成表达BDH2的慢病毒载体,构建稳定表达BDH2的肝癌细胞株HepG2-BDH2(实验组)和对照细胞株HepG2-Vector(对照组)。RT-PCR检测两组细胞中BDH2 m RNA表达...目的探讨β-羟丁酸脱氢酶2(BDH2)基因对肝癌细胞增殖能力的抑制作用及其机制。方法合成表达BDH2的慢病毒载体,构建稳定表达BDH2的肝癌细胞株HepG2-BDH2(实验组)和对照细胞株HepG2-Vector(对照组)。RT-PCR检测两组细胞中BDH2 m RNA表达水平。采用CCK-8法检测两组肝癌细胞的增殖能力,平板克隆实验观察两组细胞的克隆形成能力。Western blot检测BDH2蛋白和Bcl-2细胞凋亡相关蛋白的表达。实验数据比较采用t检验。结果实验组BDH2 mRNA表达量为(2.20±0.10)×10^(-3),明显高于对照组的(0.20±0.01)×10^(-3)(t=34.95,P<0.05)。实验组细胞培养3、4、5、6、7 d的A_(450)值分别为0.55±0.20、0.73±0.02、1.26±0.12、1.62±0.14、2.19±0.12,明显低于对照组的0.70±0.06、1.13±0.08、1.77±0.15、2.45±0.12、3.02±0.15(t=-5.19,-11.34,-5.96,-10.35,-9.54;P<0.05)。细胞生长曲线显示实验组肝癌细胞的增殖能力明显弱于对照组。平板克隆实验结果显示,实验组细胞克隆形成数目为(184±7)个,明显少于对照组的(429±15)个(t=-25.84,P<0.05)。与对照组相比,实验组的BDH2、cleaved caspase-3蛋白表达明显升高,而Bcl-2蛋白表达明显降低。结论 BDH2基因可抑制肝癌细胞增殖,其机制可能是通过Bcl-2信号通路促进肝癌细胞的凋亡。展开更多
文摘The current study describes the molecular characterization of a clone which can restore the ability of bdh A mutant strains NGRPA2 and Rm11107 to utilize 3-hydroxybutyrate as a sole carbon source (Hbu+ ). This clone was screened out by complementation experiment from Bradyrhizobium japonicum US-DAI 10 genomic library, and the presence of bdhA gene in the clone was verified by Bdh assay and Southern blot analysis. Furthermore, the entire sequence of bdhA. gene was sequenced and the sequence was deposited in GenBank database under the accession number AY077581. bdhA gene comprises 789 base pairs and encodes Bdh with 262 amino acid of MW 27.59 kDa. Interposon JlKm was inserted into the bdhA ORF at EcoR I site and the bdhA mutant was constructed in B .japonicum by homologous recombination. Plant assay result did not show obvious effects of mutation of bdhA gene on nodulation and nitrogen-fixation.
文摘This paper will correct some gaps existing in the proof of a theorem written in an earlier paper by the author on the lower bounds for sums of BDH type published in 1993. Some improvements upon the previous version of that theorem will be obtained.
