口蹄疫病毒RT-LAMP检测方法的建立

利用逆转录环介导等温核酸扩增技术(RT-LAMP),建立了口蹄疫病毒快速检测方法,同时评价了该方法的灵敏性和特异性。结果表明,根据口蹄疫病毒多聚蛋白基因保守区段设计的LAMP引物能够在65℃下,1 h内实现目标核酸区段的大量扩增,检测结果可直接用肉眼判断。该检测体系具有极高的特异性,只能检测到目标病毒,与其他类似病毒如猪水泡病病毒、猪瘟病毒、猪细小病毒等无交叉反应,可检测到10-5稀释度的目标病毒核酸量,比普通RT-PCR的灵敏性高100倍,比荧光PCR高10倍。     

西藏草地生态系统植被碳贮量及其空间分布格局

在广泛收集资料的基础上,利用平均碳密度方法,估算了西藏高原草地生态系统17类草地植被的碳贮量,并分析了其空间分布格局.结果表明:(1)17类草地植被总面积为8205.194×104hm2,总碳贮量为189.367 Tg (1TgC＝1012g),平均碳密度为2307.895 kgC/hm2,不同植被类型差异较大,在395.977～20471.161kgC/hm2之间波动;(2)从草地类型分布看,高寒草原和高寒草甸是西藏分布面积最大的2类草地,分布面积占西藏草地总面积的70.210%,又是西藏草地碳贮量的主要贮库,碳贮量占西藏草地总碳贮量的79.393%;(3)在空间分布格局上,随着自藏东南向西北的延伸,草地植被总碳密度逐次降低,这一水平分布格局与西藏独特的水热分布相一致;碳密度的垂直分布规律因地区而异,但各地区均以高寒草甸或高寒荒漠的低碳密度为终点,表现出"殊途同归"的特征.     

蛇毒类凝血酶calobin在毕赤酵母中的表达

蛇毒类凝血酶是临床上防治血栓栓塞性疾病的有效药物。参照朝鲜蝮蛇(Agkistrodon caliginosus,Korean Viper)类凝血酶calobin基因序列(GenBank AccessionNo.U32937.1),将人工合成的calobin基因克隆到酵母表达载体pPICZαA,于毕赤酵母中表达,得到了分子量约为32kD的重组calobin蛋白,经甲醇诱导培养,表达产物可获得3.5g/L的高表达量。重组蛋白经过阴离子交换柱Q-Sepharose Fast Flow和分子筛Sephacryl-S-100凝胶过滤层析等纯化步骤进行了初步纯化。纯化后的重组calobin可以在纤维蛋白原平板上形成水解圈,经SDS-PAGE实验显示,重组蛋白能水解纤维蛋白原的Aα链,产生一条约40kD左右的降解带。在实验中未能发现重组calobin对纤维蛋白原的凝固作用。     

海南省及云南西双版纳州HIV-1的分子流行病学比较研究

目的调查比较HIV-1在海南省及云南西双版纳州的流行情况及分子流行病学分析高危因素传播的情况以及传播链的鉴定。方法我们与海南省CDC及西双版纳州CDC合作在其境内开展了HIV血清学调查,筛查了海南省（1991～2006）及西双版纳州（1996～2005）高危人群志愿者血清样本。在本次两地调查中,我们通过系统进化分析方法,对已诊断的HIV感染者进行分子流行病学的追踪,来分析其中的主要流行亚群以及结合个案追踪进行传播链的鉴定。结果我们共筛查了海南省499725人,共检出HIV阳性感染者523例（0.1%）,以注射器吸毒感染为主要传播途径（经共用注射器吸毒感染占69．2％、经性接触传播占19．3％、供血和使用血液／血液制品感染占3．3％、母婴传播占0．8％、不详占7．7％）。然而,在西双版纳州筛查中发现了较海南省高20倍的检出率：在25390受检人中,共检出HIV阳性感染者501例（2％）并以异性性传播为主（经异性性接触传播占77．3％、经共用注射器吸毒感染占21．1％、经同性性接触传播占0．4％、母婴传播占1．2％）。在海南省抽样的83人中,以CRF01_-AE重组亚型（70人,84．3％）为主要病毒亚型,其他病毒亚型包括B’亚型（8人）、C亚型（2人）、CRF08_BC重组亚型（1人）、B亚型（1人）和1个未报道过的CRF01～AE／B’重组亚型。同样,在版纳抽样的44人中,也以CRF01_AE重组亚型（27人,61．3％）为主要病毒亚型,其他病毒亚型包括CRF08_BC重组亚型（15人）、G亚型（1人）、和1个未报道过的B／C重组亚型。在海南省抽样中有66人（79．5％）分布于4个大小不同的传播群,传播群1（59人）较大（奠基效应）,属于CRF01_AE重组亚型,传播群2、3、4则较小,分别为3、2、2人,分别属于CRF01_AE重组亚型、C亚型和B’亚型。相反,在版纳抽样中有18人（40．9％）分布于8个较小的传播群（每群平均含2．25感染个体）。在海南省抽样中怀疑的6对异性性接触的传播链中,经系统进化分析方法确认了其中的4对,2对被拒绝。在版纳抽样中怀疑的8对异性性接触的传播链中,经系统进化分析方法确认了其中的5对,2对被拒绝,1对无法分析,此外还新发现了3对异性性接触传播群。结论HIV-1感染者的分子流行病学的追踪和分析对于追溯艾滋病流行的源头和地区性预防策略的制定有着重大的意义。     

生物法处理木质素的研究进展

对生物法处理木质素进行了简要概述,包括微生物降解、生物法酸析提取木质素以及生物法纯化木质素的效果及其研究进展.生物法处理木质素对资源的合理利用、经济的发展以及环境保护具有重要的意义.     

Moderate desiccation dramatically improves shoot regeneration from maize (<Emphasis Type="Italic">Zea mays L.</Emphasis>) callus

Tissue and cell culture systems are vital to many areas of maize research and improvement. Efficient shoot regeneration remains a limiting factor for most elite lines. To enhance shoot regeneration, calluses derived from immature embryos of four genotypes were subjected to 6, 12, 24, 48, and 72 h of desiccation on sterile filter paper before shoot induction. We achieved up to 32% desiccation (measured as mass) and 48% imbibition (measured as mass gain in 48 h incubation) which was 3.4-fold higher than nondesiccated controls. This rapid desiccation/imbibition procedure enhanced shoot regeneration and development, but its efficiency was crucially dependent on the degree and duration of desiccation. All four genotypes calluses regenerated shoots best after 48 h of desiccation corresponding to a 23.7% average desiccation percentage, and regeneration frequencies reached 42–74%, which increased 1.5–2.1-fold compared with that of nondesiccated calluses. The effect of desiccation treatment on the shoot regeneration increase took place mainly during the early phase of induction. The weekly average shoot regeneration frequency of calluses with 48 h desiccation in the first wk reached 8.8% (the control was no regeneration); then it increased 3.0 and 2.3-fold in the second and third wk induction, respectively. We demonstrate that the moderate desiccation of calluses increases the yield of shoot regeneration and speeds up regeneration course in maize.     

NGFI-B targets mitochondria and induces cardiomyocyte apoptosis in restraint-stressed rats by mediating energy metabolism disorder

NGFI-B/Nur77/TR3, originally identified as an immediate-early gene rapidly induced by serum and growth factors, is a member of the steroid hormone nuclear receptor superfamily with no identified endogenous ligand. NGFI-B induces apoptosis in a number of cell lineages exposed to proapoptotic stimuli by directly targeting the mitochondria, inducing cytochrome c release. The present study was designed to determine the role of NGFI-B in cardiomyocytes of restraint-stressed rats. The NGFI-B content was increased in mitochondria and reduced in plasma as apoptosis increased. Analysis showed that NGFI-B induces cardiomyocyte apoptosis in restraint-stressed rats by mediating mitochondrial energy metabolism disorder. Several novel mitochondrial proteins, which correlate with NGFI-B, were reported in cardiomyocyte apoptosis of restraint-stressed rats. Five proteins associated with NGFI-B participate directly in mitochondrial energy metabolism. Studies of mitochondrial respiratory efficiency and ATP synthase activity strongly support the findings. These results provide significant information for comprehensively understanding the cellular mechanism of cardiovascular diseases.     

Fine-Scale Population Genetic Structure of Zhikong Scallop (Chlamys farreri): Do Local Marine Currents Drive Geographical Differentiation?

Marine scallops, with extended planktonic larval stages which can potentially disperse over large distances when advected by marine currents, are expected to possess low geographical differentiation. However, the sessile lifestyle as adult tends to form discrete "sea beds" with unique population dynamics and structure. The narrow distribution of Zhikong scallop (Chlamys farreri), its long planktonic larval stage, and the extremely hydrographic complexity in its distribution range provide an interesting case to elucidate the impact of marine currents on geographical differentiation for marine bivalves at a fine geographical scale. In this study, we analyzed genetic variation at nine microsatellite DNA loci in six locations throughout the distribution of Zhikong scallop in the Northern China. Very high genetic diversity was present in all six populations. Two populations sampled from the same marine gyre had no detectable genetic differentiation (F (ST) = 0.0013); however, the remaining four populations collected from different marine gyres or separated by strong marine currents showed low but significant genetic differentiation (F (ST) range 0.0184-0.0602). Genetic differentiation was further analyzed using the Monmonier algorithm to identify genetic barriers and using the assignment test conducted by software GeneClass2 to ascertain population membership of individuals. The genetic barriers fitting the orientation of marine gyres/currents were clearly identified, and the individual assignment analysis indicated that 95.6% of specimens were correctly allocated to one of the six populations sampled. The results support the hypothesis that significant population structure is present in Zhikong scallop at a fine geographical scale, and marine currents can be responsible for the genetic differentiation.