Ciliary Neurotrophic Factor-treated Astrocyte Conditioned Medium Regulates the L-type Calcium Channel Activity in Rat Cortical Neurons

Astrocytes are activated by ciliary neurotrophic factor (CNTF) in vivo and in vitro, however, the consequences on the L-type calcium channel (LCC) of neurons are still poorly understood. Therefore, in the present study, whole-cell patch clamp, western-blot and RT-PCR assay were performed to evaluate the effects of CNTF-treated astrocyte conditioned medium (CNTF-ACM) on LCC current (I_Ca-L) and the expression of Cav1.2 and Cav1.3 in Sprague–Dawley rat cortical neurons. The results revealed that CNTF-ACM enhanced the amplitude of Ica-L and the expression of Cav1.3 significantly, but had no effects on Cav1.2 expression. We also found an increase in the concentration of fibroblast growth factor-2 (FGF-2) in CNTF-ACM by ELISA assay. Taken together, these findings indicate that CNTF induces the release of factors, including FGF-2, from astrocytes, thereby potentiating the activity of LCC in cortical neurons. Xiaojing Wang and Honghua Zheng contributed equally.     

A Bat-Derived Putative Cross-Family Recombinant Coronavirus with a Reovirus Gene

The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 has generated enormous interest in the biodiversity, genomics and cross-species transmission potential of coronaviruses, especially those from bats, the second most speciose order of mammals. Herein, we identified a novel coronavirus, provisionally designated Rousettus bat coronavirus GCCDC1 (Ro-BatCoV GCCDC1), in the rectal swab samples of Rousettus leschenaulti bats by using pan-coronavirus RT-PCR and next-generation sequencing. Although the virus is similar to Rousettus bat coronavirus HKU9 (Ro-BatCoV HKU9) in genome characteristics, it is sufficiently distinct to be classified as a new species according to the criteria defined by the International Committee of Taxonomy of Viruses (ICTV). More striking was that Ro-BatCoV GCCDC1 contained a unique gene integrated into the 3’-end of the genome that has no homologs in any known coronavirus, but which sequence and phylogeny analyses indicated most likely originated from the p10 gene of a bat orthoreovirus. Subgenomic mRNA and cellular-level observations demonstrated that the p10 gene is functional and induces the formation of cell syncytia. Therefore, here we report a putative heterologous inter-family recombination event between a single-stranded, positive-sense RNA virus and a double-stranded segmented RNA virus, providing insights into the fundamental mechanisms of viral evolution.     

无溶剂体系脂肪酶动力学拆分2-辛醇及产物的非均相共沸蒸馏提取

为了提高脂肪酶在非水相中对手性仲醇的拆分效率,以2-辛醇为模式底物,建立了以辛酸为酰基供体的无溶剂脂肪酶动力学拆分手性仲醇的反应体系,采用1.5∶1的酸醇摩尔比,45℃条件下反应12 h,2-辛醇的转化率达到49.9%,并且S-2-辛醇的对映体过量率e.e.s=98.2%,反应的对映体比率E600。利用脂肪族仲醇与水形成共沸物的特性,通过非均相共沸蒸馏的方法提取拆分得到的手性仲醇,S-2-辛醇的光学纯度并未降低,并且产率大于90%,产品纯度大于98%。     

土壤线虫群落对闽北森林植被恢复的响应

为了考察地上植物群落的演替与土壤线虫群落的相互关系, 作者对闽北退化常绿阔叶林不同恢复阶段的土壤线虫群落进行了为期一年的定位研究。研究表明, 线虫群落对植被不同恢复阶段有不同的响应, 各恢复阶段线虫数量差异显著(P<0.01), 从大到小依次为: 荒地(Wj)、天然阔叶林(Cc)、针阔混交林(Clc )、针叶林(Pm); 土壤线虫数量的季节波动明显, 属数与个体密度均体现为春季＞冬季＞秋季＞夏季, 而夏季极显著少于其他季节(P<0.01); 土壤线虫群落DG指数与丰富度指数从大到小依次为天然阔叶林、荒地、针阔混交林和针叶林。而多样性顺序却表现为: 荒地>天然阔叶林>针阔混交林>针叶林; 不同恢复阶段土壤根系生物量、土壤理化特征存在明显的空间变异, 并且线虫数量与根系生物量、土壤含水率、土壤孔隙度、土壤有机质、全氮以及速效磷具有显著正相关关系。因此, 植被恢复过程中土壤线虫群落结构分异及其动态是一个重要的生态响应过程, 能为进一步研究土壤生物在植被演替中的地位和作用以及土壤生物多样性保护提供基础数据。     

蚯蚓对土壤微生物残留物的影响研究评述与展望

蚯蚓如何影响土壤有机碳的固持是土壤生态学的关键科学问题之一。蚯蚓能同时促进土壤有机碳分解和稳定,这种两面作用带来的不确定性被研究者称为"蚯蚓困境"。研究证据和新兴的"土壤微生物碳泵"概念模型表明土壤微生物残留物是土壤有机质的主要贡献者。为系统了解蚯蚓对土壤微生物残留物的影响与可能的机制,研究分析和总结了已有的国内外蚯蚓与微生物残留物（氨基糖）的相关研究成果,表明：（1）过往的研究忽略了蚯蚓对微生物残留物的影响,导致这一方向的研究严重滞后;（2）蚯蚓对土壤微生物残留物影响的方向和大小仍有很大的不确定性,可供量化分析其驱动机制的研究还很缺乏。研究尝试将蚯蚓整合到"土壤微生物碳泵"概念框架中,分析蚯蚓影响土壤微生物残留物3个方面的可能机制,即：（1）改变土壤微生物量、群落结构,（2）改变微生物生理特性,（3）改变土壤团聚体结构等,影响土壤有机碳的积累。同时,本文提出了未来相关研究的6个重点方向,包括：（1）蚯蚓对微生物的选择性取食,（2）肠道介导的微生物"涨落"现象,（3）蚯蚓对矿质结合有机物的"破坏"与"重组",（4）蚯蚓引起的"激发"和"续埋"效应,（5）多生态型相互作用,（6）全球变化背景下的蚯蚓生态学等,以期为进一步揭示蚯蚓-微生物相互作用影响土壤有机碳累积与稳定性的机制提供参考。     

Does expression of Bt toxin matter in farmer's pesticide use?

Despite the widespread adoption of Bt cotton, farmers still spray excessive pesticides in their cotton fields. In contrast to scientists who always use high quality seeds in the laboratory and/or experimental fields, farmers may plant low quality seeds with a low expression of Bt toxin. How does the expression of Bt toxin influence farmers' pesticide use? On the basis of a plot‐level survey and laboratory test data, this study shows that pesticide use on one cotton plot is influenced not only by the expression of Bt crops in this plot, but also by the average expression in the village in the early stage of the cotton growing season. In other words, high expression of Bt toxin benefits not only the farmers who plant the varieties but also all the other villagers.     

几种配合物用于食品保鲜的研究

试制了一些两价金属离子的配合物,测定了它们的吸收氧、乙烯、二氧化碳和一氧化氮的能力,用于食品保鲜的效果良好.     

Suspension culture of gametophytes of transgenic kelp in a photobioreactor

Transgenic Laminaria japonica gametophytes producing a recombinant tissue-type plasminogen activator (rtPA) protein, which is an effective third-generation thrombolytic agent for acute myocardial infarction (AMI), were cultured in an illuminated bubble column bioreactor. A maximum final dry cell weight of 1120 mg l⁻¹ was obtained in batch culture with an initial dry cell weight of 126 mg l⁻¹ and with aeration rate of 1.2 l air min⁻¹ l⁻¹ culture, nitrate at 1.5 mM and phosphate at 0.17 mM. The yield of rtPA was 56 μg g⁻¹ dry cell wt. This is the first report regarding cultivation of a transgenic macroalga in a bioreactor.Revisions requested 27 January 2005 and 14 April 2005; Revisions received 6 April 2005 and 17 May 2005     

Combined line-cross and half-sib QTL analysis of crosses between outbred lines

Data from an F 2 cross between breeds of livestock are typically analysed by least squares line-cross or half-sib models to detect quantitative trait loci (QTL) that differ between or segregate within breeds. These models can also be combined to increase power to detect QTL, while maintaining the computational efficiency of least squares. Tests between models allow QTL to be characterized into those that are fixed (LC QTL), or segregating at similar (HS QTL) or different (CB QTL) frequencies in parental breeds. To evaluate power of the combined model, data wih various differences in QTL allele frequencies (FD) between parental breeds were simulated. Use of all models increased power to detect QTL. The line-cross model was the most powerful model to detect QTL for FD>0.6. The combined and half-sib models had similar power for FD<0.4. The proportion of detected QTL declared as LC QTL decreased with FD. The opposite was observed for HS QTL. The proportion of CB QTL decreased as FD deviated from 0.5. Accuracy of map position tended to be greatest for CB QTL. Models were applied to a cross of Berkshire and Yorkshire pig breeds and revealed 160 (40) QTL at the 5% chromosome (genome)-wise level for the 39 growth, carcass composition and quality traits, of which 72, 54, and 34 were declared as LC, HS and CB QTL. Fourteen CB QTL were detected only by the combined model. Thus, the combined model can increase power to detect QTL and mapping accuracy and enable characterization of QTL that segregate within breeds.