异质水分环境下野牛草相连分株间光合同化物的生理整合及其调控

异质环境下,克隆植物通过生理整合机制使资源在分株间实现共享,提高了其对异质性环境的适应能力,具有重要的生态进化意义,研究生理整合机制及其调控机理可为进一步发掘克隆植物应用潜力提供理论依据。以野牛草3个相连分株为材料,对其中一个分株用30%聚乙二醇6000(PEG-6000)模拟水分胁迫,通过Hoagland营养液培养试验,研究了异质水分环境下光合同化物在野牛草相连分株间的生理整合及分株叶片与根系内源激素ABA与IAA含量的变化规律。结果表明,14C-光合同化物在克隆片断内存在双向运输,但以向顶运输为主,异质水分环境下,受胁迫分株光合同化物的输出率明显降低,而与其相邻分株合成的光合同化物向受胁迫分株方向运输率明显增加;异质水分环境下,各分株ABA含量均明显增加,但以受胁迫的分株叶片及根系ABA的含量增加幅度最大,各分株IAA含量较对照均显著下降(P0.05),且以受胁迫分株IAA含量下降幅度最大;各分株叶片与根系ABA/IAA均显著提高(P0.05),相邻分株ABA/IAA增加幅度低于受胁迫分株。异质水分环境影响野牛草克隆分株间光合同化物的生理整合,且ABA与IAA在分株间光合同化物运输与分配过程中具有重要的调节作用。     

基于沟眶象属两近缘种不同虫态转录组的气味受体基因鉴定及表达分析

[目的]基于沟眶象属Eucryptorrhynchus两近缘种沟眶象E.scrobiculatus和臭椿沟眶象E.brandti不同虫态的转录组数据进行气味受体(odorant receptor,OR)基因的鉴定及表达特征分析,补充两种象甲的气味受体信息,为之后的功能研究提供理论依据.[方法]从沟眶象(幼虫、蛹和成虫)...     

Comparing sources of mobility for modelling the epidemic spread of Zika virus in Colombia

Timely, accurate, and comparative data on human mobility is of paramount importance for epidemic preparedness and response, but generally not available or easily accessible. Mobile phone metadata, typically in the form of Call Detail Records (CDRs), represents a powerful source of information on human movements at an unprecedented scale. In this work, we investigate the potential benefits of harnessing aggregated CDR-derived mobility to predict the 2015-2016 Zika virus (ZIKV) outbreak in Colombia, when compared to other traditional data sources. To simulate the spread of ZIKV at sub-national level in Colombia, we employ a stochastic metapopulation epidemic model for vector-borne diseases. Our model integrates detailed data on the key drivers of ZIKV spread, including the spatial heterogeneity of the mosquito abundance, and the exposure of the population to the virus due to environmental and socio-economic factors. Given the same modelling settings (i.e. initial conditions and epidemiological parameters), we perform in-silico simulations for each mobility network and assess their ability in reproducing the local outbreak as reported by the official surveillance data. We assess the performance of our epidemic modelling approach in capturing the ZIKV outbreak both nationally and sub-nationally. Our model estimates are strongly correlated with the surveillance data at the country level (Pearson’s r = 0.92 for the CDR-informed network). Moreover, we found strong performance of the model estimates generated by the CDR-informed mobility networks in reproducing the local outbreak observed at the sub-national level. Compared to the CDR-informed networks, the performance of the other mobility networks is either comparatively similar or substantially lower, with no added value in predicting the local epidemic. This suggests that mobile phone data captures a better picture of human mobility patterns. This work contributes to the ongoing discussion on the value of aggregated mobility estimates from CDRs data that, with appropriate data protection and privacy safeguards, can be used for social impact applications and humanitarian action.     

南京农业大学微生物学虚拟仿真实验教学模式的探索

借助虚拟仿真技术构建的虚实结合的虚拟仿真实验,是提高学生实践动手能力的有力补充和有效途径。本文通过对微生物学实验教学现状的分析,探讨南京农业大学微生物学虚拟仿真实验教学模式建设的意义,重点阐述建设思路、建设方案及教学特点。该仿真实验教学体系主要从基础微生物学和应用微生物学两大模块进行构建,同时将本校的污水生物处理技术、食用菌资源调查与利用等科研成果转化为教学资源,以丰富实验教学内容。     

典型矿区植被覆盖度时空分布特征及影响因素

植被状况可以直接或间接地反映采煤对生态环境的影响。以长河井工煤矿、离柳井工煤矿、平朔露天煤矿3个典型矿区为研究区域。以Landsat数据为数据源,基于地形调节植被指数的像元二分模型提取植被覆盖度;采用趋势分析、线性回归斜率、稳定性分析方法,分析了3个典型矿区2001-2016年植被覆盖度的时空变化特征;运用"以时间换空间"的方法,采用相关分析方法对植被覆盖度变化的自然影响因素进行了分析。结果表明：（1）近16年3个典型矿区植被覆盖度呈增加趋势,长河、离柳、平朔矿区的增长速率分别为0.09%/10 a、0.10%/10 a、0.08%/10 a（P > 0.05）。（2）空间上,长河、离柳、平朔矿区植被覆盖度变化不明显比例分别占到66.63%,59.90%,62.25%,呈增加趋势的比例仅分别占28.14%、32.55%、27.81%,而呈减少趋势的比例分别占到5.23%、7.55%、9.94%。长河矿区明显改善的区域位于自然植被和耕作区的北部和东北部,离柳矿区明显改善的区域位于以低植被覆盖度为主的北部,平朔矿区明显改善的区域位于复垦的中西部。（3）不区分植被类型时,3个矿区的植被覆盖度变化与高程、高程与温度的交互作用表现出显著相关性（P < 0.01）,与各自然因素的相关性总体表现为长河 > 离柳 > 平朔矿区;区分植被类型时,草地与坡度的相关性不显著（P > 0.05）,与降雨量、高程存在显著正相关（P < 0.05）;灌木林与温度相关性不显著,与高程和降雨量的交互作用存在显著正相关;旱地与高程、高程与温度的交互作用存在显著相关性;疏林地与坡向、降雨量与坡向坡度的交互作用均没有表现出相关性;有林地与高程降雨量的交互作用表现出显著正相关性。探讨不同植被类型对自然因素的响应,可为矿区植被结构的选择,矿区复垦提供参考依据。     

Caveolin-1 identified as a key mediator of acute lung injury using bioinformatics and functional research

Acute lung injury (ALI) is a potentially life-threatening, devastating disease with an extremely high rate of mortality. The underlying mechanism of ALI is currently unclear. In this study, we aimed to confirm the hub genes associated with ALI and explore their functions and molecular mechanisms using bioinformatics methods. Five microarray datasets available in GEO were used to perform Robust Rank Aggregation (RRA) to identify differentially expressed genes (DEGs) and the key genes were identified via the protein-protein interaction (PPI) network. Lipopolysaccharide intraperitoneal injection was administered to establish an ALI model. Overall, 40 robust DEGs, which are mainly involved in the inflammatory response, protein catabolic process, and NF-κB signaling pathway were identified. Among these DEGs, we identified two genes associated with ALI, of which the CAV-1/NF-κB axis was significantly upregulated in ALI, and was identified as one of the most effective targets for ALI prevention. Subsequently, the expression of CAV-1 was knocked down using AAV-shCAV-1 or CAV-1-siRNA to study its effect on the pathogenesis of ALI in vivo and in vitro. The results of this study indicated that CAV-1/NF-κB axis levels were elevated in vivo and in vitro, accompanied by an increase in lung inflammation and autophagy. The knockdown of CAV-1 may improve ALI. Mechanistically, inflammation was reduced mainly by decreasing the expression levels of CD3 and F4/80, and activating autophagy by inhibiting AKT/mTOR and promoting the AMPK signaling pathway. Taken together, this study provides crucial evidence that CAV-1 knockdown inhibits the occurrence of ALI, suggesting that the CAV-1/NF-κB axis may be a promising therapeutic target for ALI treatment.Subject terms: Cell signalling, Respiratory tract diseases     

Age‐related memory vulnerability to interfering stimuli is caused by gradual loss of MAPK‐dependent protection in Drosophila

Age‐related memory impairment (AMI) is a common phenomenon across species. Vulnerability to interfering stimuli has been proposed to be an important cause of AMI. However, the molecular mechanisms underlying this vulnerability‐related AMI remain unknown. Here we show that learning‐activated MAPK signals are gradually lost with age, leading to vulnerability‐related AMI in Drosophila. Young flies (2‐ or 3‐day‐old) exhibited a significant increase in phosphorylated MAPK levels within 15 min after learning, whereas aged flies (25‐day‐old) did not. Compared to 3‐day‐old flies, significant 1 h memory impairments were observed in 15‐, 20‐, and 30‐day‐old flies, but not in 10‐day‐old flies. However, with post‐learning interfering stimuli such as cooling or electric stimuli, 10‐day‐old flies had worse memory performance at 1 h than 3‐day‐old flies, showing a premature AMI phenomenon. Increasing learning‐activated MAPK signals through acute transgene expression in mushroom body (MB) neurons restored physiological trace of 1 h memory in a pair of MB output neurons in aged flies. Decreasing such signals in young flies mimicked the impairment of 1 h memory trace in aged flies. Restoring learning‐activated MAPK signals in MB neurons in aged flies significantly suppressed AMI even with interfering stimuli. Thus, our data suggest that age‐related loss of learning‐activated neuronal MAPK signals causes memory vulnerability to interfering stimuli, thereby leading to AMI.     

一株裂解性奶牛乳房炎源大肠杆菌噬菌体的分离鉴定及生物学特性分析

【目的】从新疆石河子地区奶牛粪样中分离裂解性大肠杆菌噬菌体(Escherichia coli phage),对其进行纯化及生物学特性分析。【方法】利用双层平板法从奶牛粪样中分离、纯化噬菌体,将纯化后的噬菌体浓缩液用醋酸双氧铀负染后通过透射电子显微镜观察其形态特征。对该噬菌体进行全基因组测序和遗传进化分析,同时测定噬菌体的宿主谱、最佳感染复数、一步生长曲线、热稳定性及酸碱稳定性。【结果】分离并纯化出一株裂解性噬菌体vB_EcoM_XJ2,噬菌斑圆形不透明,直径0.7 mm–1.2 mm;电镜显示其头部呈正多面体对称,有可伸缩性尾部;核酸类型为双链DNA,基因组大小为75.617 kb,G+C%含量为42.09%;其核酸序列与大肠杆菌噬菌体NJ01和vB_EcoP_SU10相似性高达94%。生物学特性研究显示该噬菌体能裂解多株临床分离的大肠杆菌;能耐受60°C左右高温,在pH 5.0–11.0范围内效价稳定;最佳感染复数为0.1,潜伏期为15 min,暴发期为95 min,裂解量约为10.6 PFU/cell。【结论】vB_EcoM_XJ2是一株在不同温度、不同酸碱性环境中有较强适应能力的裂解性肌尾科大肠杆菌噬菌体。     

角毛壳菌几丁质酶基因chi58多点突变及在毕赤酵母中的高效表达

应用重叠延伸PCR技术(gene splicing by overlap extension PCR,gene SOEing),简称SOE-PCR对角毛壳菌(Chaetomium cupreum)的几丁质酶基因chi58进行多点突变.依据毕赤酵母密码子偏爱性,将毕赤酵母中编码Arg使用频率几乎为0的密码子CGC突变为使用频率高的AGA,构建了含有正确突变的酵母表达载体pPIC9K-chi58A,电转化毕赤酵母GS115,获得的重组酵母株在诱导120 h酶活力最高,平均可达101.71 U/mL±3.33 U/mL;其活力比未优化重组酵母株(31.83 U/mL±4.85 U/mL)提高了约3倍,且经10代传代培养后遗传稳定性良好.表达产物的SDS-PAGE分析表明,酶蛋白分子大小为58 kD.