普通烟草NtODB基因的电子克隆、表达及生物信息学分析

ODB基因在植物同源重组依赖性的DNA双键断裂修复过程中起重要作用,对植物诱变育种具有潜在的应用价值.克隆烟草NtODB基因并分析其表达特征为丰富ODB基因在同源重组DNA修复过程中的作用提供证据.为得到烟草NtODB基因序列,采用电子克隆技术获得该基因cDNA序列并克隆验证.进一步使用生物信息学方法分析该基因表达特征...     

我国当代微生物学课程建设与教学改革研究进展——“高等院校教学专刊”序言

积极进行微生物学教学改革经验交流,对于提高高等院校微生物学教学水平和微生物学相关人才培养质量具有重要意义。为了反映我国当代微生物学课程建设与教学改革的最新进展和发展态势,《微生物学通报》以"第十五届全国微生物学教学和科研及成果产业化研讨会"大会为契机,邀约有微生物学及相关学科教学经验的高校教师撰写稿件,通过严格评审后择优选取文章,组织出版了这期"高等院校教学专刊",期望该专刊的出版有助于我国高校微生物学教师间的教改经验交流与合作。     

Enhanced citric acid production by a yeast <Emphasis Type="Italic">Yarrowia lipolytica</Emphasis> over-expressing a pyruvate carboxylase gene

In this study, after the expression of a pyruvate carboxylase gene (PYC) cloned from Meyerozyma guilliermondii in a marine-derived yeast Yarrowia lipolytica SWJ-1b, a transformant PG86 obtained had much higher PYC activity than Y. lipolytica SWJ-1b. At the same time, the PYC gene expression and citric acid (CA) production by the transformant PG86 were also greatly enhanced. When glucose concentration in the medium was 60.0 g L^?1, CA concentration formed by the transformant PG86 was 34.02 g L^?1, leading to a CA yield of 0.57 g g^?1 of glucose. During a 10-L fed-batch fermentation, the final concentration of CA was 101.0 ± 1.3 g L^?1, the yield was 0.89 g g^?1 of glucose, the productivity was 0.42 g L^?1 h^?1 and only 5.93 g L^?1 reducing sugar was left in the fermented medium within 240 h of the fed-batch fermentation. HPLC analysis showed that most of the fermentation products were CA.     

Proteomic Analysis of Mamestra Brassicae Nucleopolyhedrovirus Progeny Virions from Two Different Hosts

Mamestra brassicae nucleopolyhedrovirus (MabrNPV) has a wide host range replication in more than one insect species. In this study, a sequenced MabrNPV strain, MabrNPV-CTa, was used to perform proteomic analysis of both BVs and ODVs derived from two infected hosts: Helicoverpa armigera and Spodoptera exigua. A total of 82 and 39 viral proteins were identified in ODVs and BVs, respectively. And totally, 23 and 76 host proteins were identified as virion-associated with ODVs and BVs, respectively. The host proteins incorporated into the virus particles were mainly involved in cytoskeleton, signaling, vesicle trafficking, chaperone and metabolic systems. Some host proteins, such as actin, cyclophilin A and heat shock protein 70 would be important for viral replication. Several host proteins involved in immune response were also identified in BV, and a C-type lectin protein was firstly found to be associated with BV and its family members have been demonstrated to be involved in entry process of other viruses. This study facilitated the annotation of baculovirus genome, and would help us to understand baculovirus virion structure. Furthermore, the identification of host proteins associated with virions produced in vivo would facilitate investigations on the involvement of intriguing host proteins in virus replication.     

The Impact of Matrix Metalloproteinase 2 on Prognosis and Clinicopathology of Breast Cancer Patients: A Systematic Meta-Analysis

Backgrounds

Matrix metalloproteinase 2 (MMP-2) plays a crucial role in the progression of breast cancer (BC). The prognostic role of MMP-2 expression in BC patients has been widely reported, but the results were inconsistent. Thus, a meta-analysis was conducted to gain a better insight into the impact of MMP-2 expression on survival and clinicopathological features of BC patients.

Methods

Identical search strategies were used to search relevant literatures in electronic databases update to August 1, 2014. Individual hazard ratios (HRs) and odds ratios (ORs) with their 95% confidence intervals (CIs) were extracted and pooled to evaluate the strength of the association between positive MMP-2 expression and survival results and clinicopathological features of BC patients. Begg’s tests, Egger’s tests and funnel plots were used to evaluate publication bias. Heterogeneity and sensitivity analysis were also assessed. All the work was completed using STATA.

Results

Pooled HRs and 95% CIs suggested that MMP-2 expression had an unfavorable impact on both OS (HR: 1.53, 95% CI: 1.29–1.82) and DFS/RFS/DDFS (HR: 1.41, 95% CI: 1.07–1.86) in BC patients. Furthermore, MMP-2 expression was significantly associated with lymph node metastasis (positive vs negative: OR 1.91, 95% CI 1.17–3.12).

Conclusion

In conclusion, positive MMP-2 expression might be a significant predictive factor for poor prognosis in patients with BC.     

Increased Risks of Mortality and Atherosclerotic Complications in Incident Hemodialysis Patients Subsequently with Bone Fractures: A Nationwide Case-Matched Cohort Study

Background

Hemodialysis (HD) patients with bone fractures have an increased risk for death. However, the risks for mortality and atherosclerotic complications in incident HD patients subsequently with bone fractures are unknown.

Methods

Data derived from the Taiwan National Health Institute Research Database between January 1997 and December 2008 was analyzed. The enrolled patients included 3,008 incident HD patients subsequently with a single long bone fracture (LB Fx) and 2,070 incident HD patients subsequently with a single non-long bone fracture (NLB Fx). These patients were matched (1:5 ratio) for age, sex, and same duration of HD with incident HD patients who had no fractures and outcomes were measured over a 3-year follow-up.

Results

After demographic and co-morbidity adjustment, LB Fx increased the risk for overall mortality (HR = 1.59, p < 0.001) and stroke (HR = 1.09, p = 0.028) in incident HD patients. NLB Fx increased the risk for overall mortality (HR = 1.52, p < 0.001), stroke (HR = 1.19, p < 0.001), coronary artery disease (CAD), (HR = 1.13, p = 0.003), and peripheral arterial occlusive disease (PAOD), (HR = 1.41, p < 0.001) in incident HD patients. Moreover, incident patients subsequently with NLB Fx had significantly higher risks of CAD and PAOD than those subsequently with LB Fx.

Conclusions

The rates of mortality and stroke were significantly higher in incident HD patients subsequently with bone fractures than in matched patients without bone fractures. Incident HD patients subsequently with NLB Fx had significantly higher risks of CAD and PAOD than those subsequently with LB Fx and without bone fractures. Thus, incident HD patients subsequently with bone fractures should be closely followed for a higher mortality and possible development of atherosclerotic complications.     

Multiple mechanisms contributed to the reduced stability of Inner Mongolia grassland ecosystem following nitrogen enrichment

Plant and Soil - Global nitrogen enrichment has been identified as a major environmental problem that poses a threat to ecosystem functioning. However, there is no consensus on the impact of...     

Genetic Diversity and Population Structure Patterns in Chinese Cherry (<Emphasis Type="Italic">Prunus pseudocerasus</Emphasis> Lindl) Landraces

Chinese cherry (Prunus pseudocerasus Lindl.) is an ancient fruit crop with highly economic and ornamental values. It originated in China and the cultivation history can be traced back to 3,000 - 4,000 years ago. Over such a long-term domestication process, a large number of genetic variations have been accumulated in different landraces. However, their utilization for cultivar improvement is limited by the scarcity of information involving genetic diversity and population structure. Here, 17 populations comprised of 140 individuals were collected from four geographic areas: Sichuan Basin (SC), Qinglin Mountain (QL), Yungui Plateau (YG) and North of China (NC), and analyzed using a set of 20 microsatellite markers. In total, 126 polymorphic loci were generated, with 6.3 loci per primer. The global expected heterozygosity (He = 0.63) and Shannon information index (I = 1.23) implied a moderately high level of genetic variation. Two major clusters (cluster 1 and cluster 2) were demonstrated based on population structure analysis, which implied the presence of two potential domestication sites of Chinese cherry landraces. Individuals from SC were assigned to cluster 1 and those from QL, YG and NC were grouped into cluster 2. Samples from QL region contained the most plentiful admixture genetic components, implied the possibility of being one transition region of genetic variation. Moreover, botanical characteristics, such as long lifespan, inbreeding preference as well as vegetative propagation, might lead to a relatively low level but significant genetic divergence among populations. Finally, conservation strategies were proposed to protect these valuable natural germplasm based on these results.