Identification of a bi-directional promoter from Tomato yellow leaf curl China virus

A bi-directional promoter of Tomato yellow leaf curl China virus (TYLCCNV) was obtained with the total DNA from TYLCCNV isolate Y10 infected tobacco leaves as a template. Plant expression vectors were constructed by fusing the amplified DNA fragment with the gus gene and nopaline terminator in different orientations. The vectors containing promoter fragments were transferred into leaf cells and plant stems of Nicotiana benthamiana by Agrobacterium-mediated method. Transient expression results showed that both the complementary and virion-sense promoters could drive the gus gene to express, and the GUS activity of the complementary-sense promoter was stronger than that of the virion-sense. Co-expression of the vector containing βC1 gene of TYLCCNV DNAβ with the vector containing a bi-directional promoter revealed that the βC1 protein has no impact on expression of either the virion- or the complementary-sense promoter.     

Identification of a bi-directional promoter from Tomato yellow leaf curl China virus

A bi-directional promoter of Tomato yellow leaf curl China virus (TYLCCNV) was obtained with the total DNA from TYLCCNV isolate Y10 infected tobacco leaves as a template. Plant expression vectors were constructed by fusing the amplified DNA fragment with the gus gene and nopaline terminator in different orientations. The vectors containing promoter fragments were transferred into leaf cells and plant stems of Nicotiana benthamiana by Agrobacterium-mediated method. Transient expression results showed that both the complementary and virion-sense promoters could drive the gus gene to express, and the GUS activity of the complementary-sense promoter was stronger than that of the virion-sense. Co-expression of the vector containing βC1 gene of TYLCCNV DNAβ with the vector containing a bi-directional promoter revealed that the βC1 protein has no impact on expression of either the virion- or the complementary-sense promoter.     

Effects of electrolysis on Microcystis aeruginosa in water

Microcystis aeruginosa (blue-green algae) is of concern in relation to drinking water because of its ability to produce toxins and odors that can significantly impair water quality. The drinking water contaminated with toxic cyanobacteria could cause the death of the domestic and wild animals and the cases of human illness. To minimize the threat, the treatment of eutrophicated water containing algae (M.aeroginosa) was conducted via electrochemical oxidation process, with titanium based anode coated with RuO₂ in this study. The research showed that the electrochemical oxidation process was effective in inhibiting the growth of the algae such as M.aeruginosa. The electrolysis parameters such as: electrolysis time, current density, and electrodes distance were analyzed by the orthogonal collocation method. The results showed the electrolysis time was the dominant factor for the inhibition of the algal growth. The optimal operating conditions were: current density of 10 mA/cm² and the electrodes distance of 6 cm. The inhibitive efficiency was 92.64% with the electrolysis time of 40 minutes. The preliminary mechanism of this process was also explored and proposed in this paper.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most e?ective isolate.     

Tissue-specific expression of glutathione S-transferases induced by 2-tridecanone or quercetin in cotton bollworms, Helicoverpa armigera (Hübner)

The tissue-specific expression of glutathione S-transferases (GSTs) in the cotton bollworm and the expression level induced by 2-tridecanone and quercetin were examined using the methods of biochemistry and the quantitative PCR. The relative expression level of GST mRNA was unanimous with the GSTs activity conjugaging with 1-chloro-2, 4-dimitro-benzene (CDNB) in fat bodies, midguts, heads and integuments of cotton bollworms. The GSTs activity in fat bodies was the highest, then midguts, heads and integuments in turn, which was in consistent with the relative expression level of GST mRNA. The specific activity of GSTs and the relative expression level of GST mRNA could be significantly induced by 2-tridecanone and quercetin, and after the induction the order of the GSTs activity and the relative expression level of GST mRNA in the above four tissues in cotton bollworms was not different from the control. The induction of GSTs by 2-tridecanone was stronger than by quercetin in all four tissues, which was in accordance with the relative expression level of GST mRNA. It suggested that the increase of GSTs activity induced by plant allelochemicals was associated with the elevated expression of GST mRNA in cotton bollworms.     

C-banding pattern and nucleolar organizer regions of Cynoglossus semilaevis Günther, 1873

The C-banding pattern and nucleolar organizer regions of the metaphase chromosomes of Cynoglossus semilaevis are reported. The interstitial regions in all chromosomes including the pair of sex chromosomes had positive C-bands, and the 6th and 12th pairs of chromosomes were entirely stained in most cases. Some chromosomes such as the 1st, 2nd, 7th, 8th, 9th and 10th pairs showed C-bands at centromeric or distal ends. The C-banding heretochromatin occupies 30.03% of the total chromosome surface in C. semilaevis, which is similar to that of amphibians such as Mixophyes fasciolatus (30.2%) and M. schevilli (20.7%), but is rather lower than that of cephalochordate Branchiostoma belcheri (54.3%). Silver staining revealed a single pair of nucleolar organizer regions (NORs) located in the telomeric regions of Chromosome 2. The association of NORs with heterochromatin observed in vertebrates also occurs in C. semilaevis as the telomeric regions of Chromosome 2 are always stained positively with C-banding.     

斜带石斑鱼ERP44基因的克隆与表达分析

为进一步了解内质网蛋白44基因(ERP44)在石斑鱼免疫反应中的作用,本研究根据实验室石斑鱼转录组数据中ERP44的表达序列标签(EST)设计引物,克隆了斜带石斑鱼(Epinephelus coioides)Ec-ERP44基因的开放阅读框序列(ORF),利用生物信息学手段分析Ec-ERP44基因及其编码蛋白的序列结构和特征,并通过实时荧光定量PCR检测该基因的组织分布特征,以及脂多糖(Lipopolysaccharide, LPS)、聚肌胞苷酸(Polyinosinic-polycytidylic acid, Poly I:C)刺激后该基因在石斑鱼脾脏中的表达变化。研究结果表明,Ec-ERP44基因ORF全长1 233 bp,编码410个氨基酸;该蛋白具有蛋白质二硫键异构酶(PDI)家族保守的硫氧还蛋白结构域。同时,Ec-ERP44基因在健康石斑鱼体内的多种组织均有表达,其中在脑组织中的表达量最高;在LPS与Poly I:C刺激后,石斑鱼脾脏中Ec-ERP44基因的表达显著上调。本研究结果表明,Ec-ERP44基因参与了石斑鱼抗病原感染的免疫反应。     

Climate-mediated energetic constraints on the distribution of hibernating mammals

To predict the consequences of human-induced global climate change, we need to understand how climate is linked to biogeography. Energetic constraints are commonly invoked to explain animal distributions, and physiological parameters are known to vary along distributional gradients. But the causal nature of the links between climate and animal biogeography remain largely obscure. Here we develop a bioenergetic model that predicts the feasibility of mammalian hibernation under different climatic conditions. As an example, we use the well-quantified hibernation energetics of the little brown bat (Myotis lucifugus) to parameterize the model. Our model predicts pronounced effects of ambient temperature on total winter energy requirements, and a relatively narrow combination of hibernaculum temperatures and winter lengths permitting successful hibernation. Microhabitat and northern distribution limits of M. lucifugus are consistent with model predictions, suggesting that the thermal dependence of hibernation energetics constrains the biogeography of this species. Integrating projections of climate change into our model predicts a pronounced northward range expansion of hibernating bats within the next 80 years. Bioenergetics can provide the simple link between climate and biogeography needed to predict the consequences of climate change.     

Overexpression of rice OsLOL2 gene confers disease resistance in tobacco to Pseudomonas syringae pv. Tabaci

LSD1-related proteins of Arabidopsis with LSDl-like zinc finger domains regulate disease resistance and programmed cell death （PCD）. We cloned a rice OsLOL2 gene, orthologous to LSD1 of Arabidopsis and expressed it in a tobacco plant. Transgenic tobacco lines displayed enhanced disease resistance to a virulent bacterium Pseudomonas syringae pv. tabaci （Pst）. RT-PCR analysis showed that overexpression of OsLOL2 in transgenic tobacco lines resulted in upregulation of two pathogenesis-related （PR） protein genes, PR2 and PR5. Our results suggest that overexpression of OsLOL2 in transgenic tobacco enhances the resistance through the induction of PR proteins and hypersensitive response-like reaction.     

Analysis of IGF2 mRNA expression and its methylation status between cattle yaks and their parents

Cattle yaks are an F1 hybrid between cattle and yaks and exhibit significant hybrid vigor. However, cattle yaks are sterile males. To study the epigenetic aspects of this reproductive isolation, IGF2 mRNA expression in cattle yaks and their parents and the patterns of the IGF2 differentially methylated regions (DMR) were examined in blood and testes. The results showed that IGF2 expression in cattle yaks’ testes was lower than in their parents (P < 0.01). The IGF2 DMR was highly methylated (above 90%) in blood and testes of cattle yaks, yaks and cattle, with the highest level in cattle yaks (P > 0.05). Our study showed that IGF2 plays an important role in bovine spermatogenesis and might be involved in cattle-yak male sterility. The methylation level of the IGF2 DMR was irrelevant to the lower expression of IGF2 in cattle yaks; other factors perhaps play roles in its expression.     

柞蚕蛹培养蝉花的孢子粉和孢梗束的代谢组分析

已有研究表明,人工培养蝉花与野生蝉花的功效非常相似,具有替代野生蝉花的潜力。本实验通过基于HPLC-TOF/MS的代谢组学的方法,将人工蝉花孢子部分和孢梗束部分进行代谢物组差异分析比较。分析柞蚕蛹培养的蝉花孢子部分和孢梗束部分代谢产物的差异,将为开发蝉花活性部位产品提供理论依据。结果表明,柞蚕蛹培养蝉花的孢子部分和孢梗束部分之间的代谢产物差异显著。经谱库检索鉴定,得到88个差异化合物,其中78个化合物在孢子部分含量较高。柞蚕蛹培养蝉花的孢子和孢梗束之间代谢组显著不同,孢子部分含有较多的生物活性物质和营养物质,因此,柞蚕蛹培养蝉花的孢子粉具有较大开发潜力。     

方格星虫生物活性成分的研究进展

方格星虫(Sipunculus nudus)是重要的经济类底栖动物,具有重要的食用和药用价值,它含有多种生物活性成分,如多糖、多肽及蛋白质等,具有增加免疫、延缓衰老、抗疲劳等生理功能。本文对方格星虫中生物活性成分的提取分离、纯化、结构分析及药理作用等进行综述,为方格星虫资源的深入研究和开发提供借鉴。