Identification of Antigens Common to Streptococcus suis Serotypes 2 and 9 by ImmunoproteomicAnalysis

Streptococcus suis is a Gram-positive pathogen that causes serious diseases in pigs. In addition to S. suis serotype 2 (SS2), S. suis serotype 9 (SS9) is another prevalent serotype, which is frequently isolated from the organs of diseased pigs in China. An immunoproteomic-based approach was developed to identify antigens common to SS2 and SS9 for vaccine development. Cell wall proteins extracted from SS2 strain HA9801 were screened by two-dimensional Western blot using anti-SS2 sera, anti-SS9 sera, or pre-immune sera pooled from specific pathogen free (SPF) mice. Protein spots on preparative gels were excised and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which led to the identification of four shared immunogenic proteins (arginine deiminase, translation elongation factor-Ts, o-acetylserine lyase, and 1-phosphofructokinase). The genes encoding these four proteins from SS9 strain GZ0565 were cloned and their proteins were overexpressed in Escherichia coli BL21. Western blot analysis of these recombinant proteins using the convalescent serum of an SPF mini-pig inoculated with the SS2 strain, anti-SS2 sera, and anti-SS9 sera pooled from SPF mice further confirmed the immunogenicity of these proteins. These immunogenic proteins, which are encoded by genes that are reasonably conserved among SS2 and SS9 strains, could be developed as vaccine candidates.     

冻融作用对黑土重金属Zn形态转化的影响

通过对重金属Zn污染的黑土进行冻融频次和不同含水量的实验研究得到,随着冻融次数的增加,重金属Zn交换态含量,铁锰氧化物结合态含量和有机结合态含量均呈不同程度的降低趋势,残渣态含量明显增加,表明冻融作用可使土壤重金属Zn生物有效态含量降低。重金属Zn各赋存形态含量与土壤所经历的冻融次数之间呈二次多项式的函数关系,相关系数在0.948和0.988之间。随着土壤含水量的增加,冻融作用对重金属Zn交换态含量影响不大,铁锰氧化物结合态含量降低,有机结合态含量增加,而残渣态含量明显增加。     

寒地水稻优质RNA提取技术优化

空育131和稻花香是黑龙江省很有代表性的寒地栽培品种,也是育种研究的重要材料。为了获取此品种的优质RNA,以经低温避光处理3d的空育131及稻花香水稻的10日龄水稻苗叶为材料,利用优化的UNIQ-10柱式Total RNA Extractor(Trizol)试剂盒法提取RNA。之后,进行RT-PCR反应,并对RT-PCR的结果进行琼脂糖凝胶电泳的检测。结果表明:通过优化,改进了UNIQ-10柱式Total RNA Extractor(Trizol)试剂盒法,提取的RNA纯度较高,A260/A280均接近1.8,并且RT-PCR的条带清晰。