Computer-Aided Drug Design (CADD) to De-Orphanize Marine Molecules: Finding Potential Therapeutic Agents for Neurodegenerative and Cardiovascular Diseases

Computer-aided drug design (CADD) techniques allow the identification of compounds capable of modulating protein functions in pathogenesis-related pathways, which is a promising line on drug discovery. Marine natural products (MNPs) are considered a rich source of bioactive compounds, as the oceans are home to much of the planet’s biodiversity. Biodiversity is directly related to chemodiversity, which can inspire new drug discoveries. Therefore, natural products (NPs) in general, and MNPs in particular, have been used for decades as a source of inspiration for the design of new drugs. However, NPs present both opportunities and challenges. These difficulties can be technical, such as the need to dive or trawl to collect the organisms possessing the compounds, or biological, due to their particular marine habitats and the fact that they can be uncultivable in the laboratory. For all these difficulties, the contributions of CADD can play a very relevant role in simplifying their study, since, for example, no biological sample is needed to carry out an in-silico analysis. Therefore, the amount of natural product that needs to be used in the entire preclinical and clinical study is significantly reduced. Here, we exemplify how this combination between CADD and MNPs can help unlock their therapeutic potential. In this study, using a set of marine invertebrate molecules, we elucidate their possible molecular targets and associated therapeutic potential, establishing a pipeline that can be replicated in future studies.     

Inter-Alu PCR like genomic profiling in banana

Alu sequences are a major repetitive element of the primate genome. To date Alu sequences have seldom been reported in plant genomes. We report here an inter-Alu PCR like genomic profiling in banana using a single primer designed from a human Alu sequence. The different Musa species involved in the complex genome of banana cultivars can thus be discriminated. The use of this technique for monitoring germplasm or genotyping cultivars is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Proximal remote sensing to differentiate nonviruliferous and viruliferous insect vectors – proof of concept and importance of input data robustness

Proximal remote sensing is being widely studied as a noninvasive method to partially automate diagnostics of plants and insects. The hypothesis that proximal remote sensing can be used to differentiate specimens of adult beet leafhoppers (Circulifer tenellus) that were nonviruliferous or viruliferous for beet curly top virus (BCTV) was tested. A key aspect of applications of proximal remote sensing is the ‘robustness’ or repeatability of input reflectance data. Many factors may contribute to low input reflectance data robustness; these include: (i) issues related to the consistency of proximal remote sensing conditions (light intensity and spectral composition, ambient temperature), (ii) insect specimen preparation (projection angle, storage and handling), and (iii) insect specimen characteristics (age, growing conditions, variety/biotype, host plant). This study demonstrates that nonviruliferous and viruliferous specimens of adult beet leafhoppers possess unique body reflectance features and, therefore, can be differentiated. However, insect specimen preparation (removal of wings and placement) markedly affected the classification accuracy. Addition of experimental noise to input reflectance data was conducted to simulate varying degrees of input reflectance data robustness. The potential of developing reflectance-based diagnostic tools for detection of plant pathogenic viruses in insects is discussed, with an emphasis on input data robustness.     

小菜蛾Gadd45g基因的克隆、表达谱及RNA干扰对小菜蛾羽化过程的影响

为探讨生长阻滞和DNA损伤诱导基因Gadd45g对小菜蛾Plutella xylostella生长发育的影响及其对蜕皮激素类似物的响应,利用全长cDNA末端的快速克隆(rapid amplification of cDNA ends,RACE)技术克隆小菜蛾Gadd45g的全长序列并进行生物信息学分析,采用实时荧光定量PCR技术分析不同龄期及不同浓度虫酰肼处理后Gadd45g基因的表达水平;同时利用dsRNA注射法干扰蛹期小菜蛾Gadd45g基因,分析该基因对蛹期特异基因Br-Z2/3表达量及小菜蛾羽化进程的影响。结果显示,小菜蛾Gadd45g基因序列全长为1 479 bp,其中编码区序列长度为495 bp,可编码164个氨基酸,GenBank登录号为MW160738。小菜蛾GADD45γ蛋白与鳞翅目昆虫的GADD45同源性最高,与脊椎动物的同源性较低。Gadd45g基因在小菜蛾全龄期均有表达,其中在蛹期的相对表达量最高,显著高于其他龄期,并在蛹期和成虫期具有明显的性别表达差异;低剂量虫酰肼处理后小菜蛾Gadd45g基因相对表达量显著上升。干扰Gadd45g基因表达后小菜蛾蛹期特异基因...     

穗茎兼收鲜食玉米收获机割台自适应仿形系统研制

为了解决穗茎兼收鲜食玉米收获机割台仿形存在的问题,基于超声测距原理,研制了一种穗茎兼收鲜食玉米收获机的割台自适应仿形系统。该系统中,超声波测距传感器安装在割台分禾器前端,用于实时检测割台分禾器与地面高度差,将高度差信号传输至玉米收获机的中心控制终端,由控制终端发出相应调整指令,控制割台调整液压系统进行割台高度调整,实现玉米收获机在作用过程中的割台自适应仿形。以190kW四行的穗茎兼收鲜食玉米收获机为样机,搭载所研制的割台自适应仿形系统,开展仿形系统验证试验,玉米机作业行走平均速度4km/h,割台转速400r/min,安装在2个超声波测距传感器,割茬高度控制在90-110mm范围内,试验结果显示,在累计作业8小时的整个过程中,割台调整平稳,割台无触地现象,试验结果验证了所研制的割台仿形系统的有效性。     

腰果角盲蝽气味结合蛋白基因HtheOBP3的克隆及组织表达分析

为明确腰果角盲蝽Helopeltis theivora气味结合蛋白3(odorant binding protein 3,OBP3)功能及其嗅觉感受机制，利用PCR技术结合c DNA末端快速扩增（rapid amplification of c DNA ends,RACE）技术克隆其cDNA全长序列，利用多个生物信息学软件对其进行序列分析，并通过实时荧光定量PCR(real-time quantitative PCR,qPCR)技术检测其在腰果角盲蝽成虫不同组织中的表达量。结果显示，腰果角盲蝽HtheOBP3基因（GenBank登录号为QHI06949）开放阅读框为474 bp，编码157个氨基酸残基，预测蛋白分子量约为17.15 kD，等电点为5.14，无信号肽和跨膜结构，蛋白氨基酸序列中具有6个保守半胱氨酸残基和性信息素结合蛋白-普通气味结合蛋白（pheromone binding protein-general odorant binding protein,PBP-GOBP）家族的保守结构域。HtheOBP3蛋白具有6个α-螺旋和3对二硫键，其中5个α-螺旋形成1个结合口袋。腰...     

油菜铺膜打孔播种机滚动式割膜打孔装置设计与试验

针对现有油菜播种膜上成穴打孔装置实际作业过程中存在膜孔尺寸偏大、形状不规则及膜孔粘连等问题，基于滑切原理设计了一种滚动式割膜打孔装置，确定了打孔装置和仿形机构结构参数，建立了打孔装置运动学模型，分析确定了影响膜孔长度的主要因素及其取值范围。运用DEM-MFBD耦合仿真，采用三因素三水平回归正交试验，以整机前进速度、纵向刀片长度、纵向刀片高度为试验因素，膜孔长度和孔距差值为评价指标进行仿真试验，结果表明：各因素对膜孔长度的影响由大到小依次为纵向刀片长度、整机前进速度、纵向刀片高度，各因素对孔距差值的影响由大到小依次为纵向刀片高度、整机前进速度、纵向刀片长度。整机前进速度为3.3 km/h、纵向刀片长度为34 mm、纵向刀片高度为31 mm时，膜孔长度为44.78 mm、孔距差值为0.64 mm,打孔性能较优。以较优参数组合开展了滚动式割膜打孔装置田间试验，结果表明膜孔平均长度为43.15 mm,膜孔长度稳定性变异系数为3.86%,平均孔距差值为-1.32 mm,膜孔孔距误差为4.22%,满足油菜播种割膜打孔要求，该研究可为油菜铺膜播种机割膜打孔装置提供参考。     

陆地棉BGLU基因家族成员的全基因组鉴定与表达分析

植物BGLU基因在生物和非生物胁迫防御中起着重要作用，利用生物信息学手段对陆地棉（Gossypium hirsutum） BGLU家族成员进行全基因组鉴定，对序列特征、保守域结构、染色体定位、启动子元件等家族特征进行了分析，并进一步结合转录组数据和qRT-PCR分析了BGLU基因家族的病菌胁迫响应模式。结果表明，共鉴定出53个陆地棉BGLU基因，根据系统发育进化关系分为6个亚族，部分基因在病菌胁迫下特异性表达。荧光定量和转录组测序结果表明，GhBGLU5、GhBGLU14、GhBGLU18、GhBGLU26、GhBGLU34在抗病棉花中的表达水平显著高于感病品种，推测这些基因正向调控棉花黄萎病抗性。上述结果为进一步分析棉花BGLU家族基因的功能以及分子机制提供一定的理论基础。