DLGCN:基于图卷积网络的药物-lncRNA[]关联预测

为实现高通量识别新的药物-长链非编码RNA(Long non-coding RNA, lncRNA)关联,本文提出了一种基于图卷积网络模型来识别潜在药物-lncRNA关联的方法DLGCN(Drug-LncRNA graph convolution network)。首先,基于药物的结构信息和lncRNA的序列信息分别构建了药物-药物和lncRNA-lncRNA相似性网络,并整合实验证实的药物-lncRNA关联构建了药物-lncRNA异质性网络。然后,将注意力机制和图卷积运算应用于该网络中,学习药物和lncRNA的低维特征,基于整合的低维特征预测新的药物-lncRNA关联。通过效能评估,DLGCN的受试者工作特性曲线下面积(Area under receiver operating characteristic, AUROC)达到0.843 1,优于经典的机器学习方法和常见的深度学习方法。此外,DLGCN预测到姜黄素能够调控lncRNA MALAT1的表达,已被最近的研究证实。DLGCN能够有效预测药物-lncRNA关联,为肿瘤治疗新靶点的识别和抗癌药物的筛选提供了重要参考。     

高寒山区植物根抗氧化酶系统的季节变化与抗冷冻关系

在高寒山区（海拔2900m）和选取4种多年生草本植物,即无芒雀麦（Bromus inermis）、草地早熟禾（Poa sphyondylodes）、花誉麦（Bromus sinensis）和垂重申披碱草（Elymus nutans）,测定了秋末、冬初、冬季、春季气温变化过程中其根中丙二醛（MDA）含量和抗氧酶活力（过氧化氢酶（CAT）、过氧化物酶（POD）、超氧物歧化酶（SOD））和抗坏血酸氧化酶（APX）变化,分析了抗氧酶系统在根抗冷适应中的作用,结果表明,随秋末降温植物根中MDA含量增加,尔后下降,在冬季和翌年春季保持相对稳定。从9月初到10月下旬,4种植物根中SOD、CAT、POD活力平均增加170％、130％和56％。在冬季下降,但仍远高于9月,在春季气温上升过程中酶活力上升。根能在组织结冰状况下生存与其具备完善的保护酶系统,能及时清除氧自由基抑制膜脂过氧化维持膜完整性有关,据降温过程中MDA含量和抗氧酶活力变化,可将根冷适应分为两个阶段,即第1阶段平均气温在0℃以上,抗氧酶活力增强,MDA增加阶段,第2阶段平均气温降至0℃以下,最低气温降到－15℃以下,抗氧酶活力下降,MDA无明显变化阶段。     

MASS ESTIMATE AND EVOLUTIONARY TREND IN CHINESE MESOZOIC FOSSIL BIRDS

体重是一项重要的生物学指标,生物的体重受到发育、繁殖和进化等诸多因素的影响.对于灭绝生物体重的估计有助于进一步恢复它们的各种生物学信息.本研究采用统计学的方法,对422件现生鸟类(分属于21目229种)的体重和18项骨骼量度指标分别进行一元回归分析,结果显示判定系数的分布范围在0.5 ～0.91之间,多数指标的判定系数均集中在0.8 ～0.9之间.采用另外64件测量有体重数据和骨骼量度的鸟样本对回归方程的估算准确率进行检验,发现前肢中肱骨长度和尺骨宽度以及后肢中胫跗骨宽度3项指标的估算准确率高于其他指标.分析结果还表明前肢两项指标对于估算鸣禽、猛禽和攀禽类等树栖鸟类的体重准确率较后肢显著;后肢指标对于估算陆禽类等地栖鸟类体重的准确率高于前肢指标.这一结果反映出与体重相关程度较高的骨骼量度指标在不同习性的鸟类当中存在着一定的差异.对于化石鸟类的体重估计,采用估算准确率较高并且便于测量的肱骨长度和胫跗骨宽度两项回归方程加以计算.通过对中国中生代鸟类的体重进行估算,结果显示中生代鸟类在系统发育过程中,反鸟类经历了体重逐渐减轻的过程,而今鸟类的体重开始不断增大并且出现显著的分异.     

Specific endotoxic lipopolysaccharide-binding receptors on murine splenocytes. III. Binding specificity and characterization.

In previously published studies, we employed a photoreactive radioiodinated derivative of LPS from Escherichia coli 0111:B4 to identify and characterize a membrane-localized specific LPS binding protein of approximately 80-kDa molecular mass. Our more recent studies demonstrating that mAb with specificity for this 80-kDa protein will act as an agonist in mediating macrophage activation have established that this protein serves as a specific receptor for LPS. In the experiments reported here, we have more accurately determined the apparent molecular mass of this protein to be 73 kDa (p73). We have also extended the sources of LPS-derivatized photo-cross-linking preparations (including Re-LPS) to determine generality of LPS binding to this receptor. Binding to the p73 LPS receptor is demonstrated with all of the LPS derivatives synthesized in our laboratory, as well as probes synthesized by other investigators. Binding of S-LPS is readily inhibited by Re chemotype LPS, and we have shown that this competitive inhibition is most likely not the result of formation of LPS aggregates. These results confirm and extend our earlier studies suggesting that the binding of LPS to the p73 receptor is lipid A specific. We further demonstrate that, in contrast to results published in a recent report, the p73 LPS receptor has no significant binding specificity for a variety peptidoglycan polymer preparations. Finally, we show that this LPS receptor can be detected on murine fibroblast, macrophage, and mastocytoma cell lines. Differences have been observed in the level of expression of LPS receptors on the various cell lines studied.     

孕期应激对子代大鼠骨髓淋巴干细胞发育的影响

孕期应激对子代产生的影响是多方面的,这种影响是复杂的。研究表明,出生前的应激经历可导致出生后子代长期的免疫功能改变。这些改变追其根源与骨髓淋巴干细胞的改变有关。本文综述了大鼠孕期经历应激的子代骨髓淋巴干细胞所受的影响及免疫系统的相关改变,并根据现有的研究提出假说,为进一步研究孕期应激导致子代免疫系统改变的机理研究提供新的思路。     

对生化分离技术实验的探讨

实验教学的改进和提高,是教学改革的重要一环。阐述了作者在教学实践的过程中,对生化分离技术实验中的原料选取、处理方法、仪器设备等方面所作的改进尝试而取得的成效。     

江西阳际峰自然保护区陆生贝类物种多样性

2007年11月～2008年5月调查了江西阳际峰自然保护区陆生贝类资源,共采得陆生贝类47种(含2个未定种),隶属13科27属,其中16种为江西省陆生贝类新纪录种.区系分析表明,该保护区陆生贝类以东洋界成分为主,占种类总数的63.83%.其优势种为墙草真管螺和同型巴蜗牛.分析11个采集点生物多样性指数结果表明,Margalef丰富度指数(dMA)范围为0～6.2345;Shannon-Wiener多样性指数( H ′)范围为0～3.5676;Pielou均匀度指数( Jsw )范围为0～1.3610.环境越复杂,种类组成越丰富;物种分布越均匀的地区,陆生贝类多样性指数就越高.     

Engineering mouse apolipoprotein A-I into a monomeric, active protein useful for structural determination

Apolipoprotein AI (apoAI), the major protein component of HDL, is one of the best predictors of coronary artery disease (CAD), with high apoAI and HDL levels being correlated with low occurrences of CAD. The primary function of apoAI is to recruit phospholipid and cholesterol for assembly of HDL particles. Like other exchangeable apolipoproteins, lipid-free apoAI forms a mixture of different oligomers even at 1.0 mg/mL. This self-association property of the exchangeable apolipoproteins is closely associated with the lipoprotein-binding activity of this protein family. It is unclear if the self-association property of apolipoprotein is required for its lipoprotein-binding activity. We developed a novel method for engineering an oligomeric protein to a monomeric, biologically active protein. Using this method, we generated a monomeric mouse apoAI mutant that is active. This mutant contains the first 216 residues of mouse apoAI and replaces six hydrophobic residues with either polar or smaller hydrophobic residues at the defined positions (V118A/A119S/L121Q/T191S/T195S/T199S). Cross-linking results show that this mutant is greater than 90% monomeric at 8 mg/mL. CD, DSC, and NMR results indicate that the mutant maintains an identical secondary, tertiary structure and stability as those of the wild-type mouse apoAI. Lipid-binding assays suggest that the mutant shares an equal lipoprotein-binding activity as that of the wild-type apoAI. In addition, both the monomeric mutant and the wild-type protein make nearly identical rHDL particles. With this monomeric mouse apoAI, high-quality NMR data has been collected, allowing for the NMR structural determination of lipid-free apoAI. On the basis of these results, we conclude that this apoAI mutant is a monomeric, active apoAI useful for structural determination.     

人类新基因WDR24的研究初报

WD40家族是一类结构保守、功能复杂的蛋白.目前很多研究显示该家族成员通过参与MAPK信号途径调控细胞内信号转导而影响细胞的基本生命活动.为了鉴定参与细胞生命活动的新基因,运用同源基因克隆法,通过PCR技术扩增获得一个新的人类基因WDR24, 其cDNA全长3 302 bp,2 373 bp长的开放阅读框编码由790个氨基酸残基组成的蛋白质.生物信息学分析表明,WDR24蛋白在进化上高度保守,与其他脊椎动物中的同源蛋白组成了一个功能未知的亚家族.蛋白序列分析显示其中有6个WD40重复序列和1个ERK的停泊位点D-domain.RT-PCR分析表明,该基因在所有被检测的人类胚胎组织中表达.     

生态脆弱带不同区域近缘优势灌木的生理生态学特性

小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿分别为中国北方生态脆弱带典型区域——科尔沁沙地、毛乌素沙地和腾格里沙漠的优势灌木。为了探讨生长在地理位置相距很远的不同气候类型区、但亲缘关系较近的沙漠植物种之间特性的差异及近缘种间引种成功的可能性 ,对 3种灌木在原产地和引种地 (腾格里沙漠 )的气体交换、叶绿素荧光参数、β胡萝卜素和脯氨酸累积等特性进行了对比研究 ,结果显示 :各区优势灌木的气体交换特征不同 ,主要依照区域光照和温湿条件的不同组合而变化 ,各区域的环境条件组合最利于其建群种的生长 ;引进种对引种地环境变化的反应调节较乡土种敏感 ;地理位置相距较近的近缘种间生理特性相近 ,引种易于成功