唇鱼骨基因组DNA提取与ISSR-PCR的优化

以唇鱼骨为材料,分别采用4种不同方法(CTAB法、SDS法、ROSE法及试剂盒)提取基因组DNA,并对影响PCR反应的模板DNA、引物、dNTPs、Mg2+、Taq酶浓度等主要因子进行了优化,建立了适合唇鱼骨基因组DNA的ISSR-PCR反应体系.25μL的PCR反应液含有的组分和终浓度分别为:约60 ng模板DNA,1.2 U Taq酶,0.4 μrnol/L引物,2.0 mmol/L MgCl2,0.2 mmol/L dNTPs,2%甲酰胺.结果表明,利用优化反应体系对4种不同方法提取的DNA进行PCR扩增,均能得到较好的PCR扩增条带,以试剂盒法最佳,为淡水溪流性同属鱼类遗传多样性分析奠定了技术基础.     

2-(3,4-二甲氧基苯基)-4,5-二苯基-1H-咪唑与DNA相互作用的荧光光谱研究

运用荧光猝灭法研究了2-(3,4-二甲氧基苯基)-4,5-二苯基-1H-咪唑(I)与鲱鱼精DNA的相互作用,用Stern-Volmer方程和Lineweaver-Burk双倒数函数方程对数据进行了处理.结果表明,两者之间形成了配合物,且得到了319 K时的静态猝灭结合常数(KLB=80.74 L.g-1)和结合位点数(n=0.78254).     

Edge computing oriented virtual optical network mapping scheme based on fragmentation prediction

As edge computing services soar,the problem of resource fragmentation situation is greatly worsened in elastic optical networks(EON).Aimed to solve this problem,this article proposes the fragmentation prediction model that makes full use of the gate recurrent unit(GRU)algorithm.Based on the fragmentation prediction model,one virtual optical network mapping scheme is presen-ted for edge computing driven EON.With the minimum of fragmentation degree all over the whole EON,the virtual network mapping can be successively conducted.Test results show that the pro-posed approach can reduce blocking rate,and the supporting ability for virtual optical network serv-ices is greatly improved.     

经济增长对森林破碎化的影响——以中国京津冀地区为例

【目的】研究京津冀地区经济增长对森林资源造成的影响及其内在影响机制,为该地区进一步实现经济与生态的协调可持续发展提供参考。【方法】以京津冀地区为例,通过2000—2018年卫星遥感影像数据测度京津冀地区38个样本县的森林破碎化程度,采用森林转型理论、土地利用变化理论以及生长轴理论等构建经济增长、交通基础设施建设以及森林破碎化三者间的中介效应模型,并进行实证检验。【结果】经济增长水平与京津冀地区森林破碎化程度关系,同一时期内,经济增长水平每提高1%,森林破碎化程度的加深超过3%;经济增长水平与京津冀地区的交通基础设施建设关系表明,经济增长水平每提高1%,京津冀地区的公路密度的增长量超过0.1%;交通基础设施建设与京津冀地区的森林破碎化关系表明,每提高1个单位的公路密度将使得该地区增加超过4个森林斑块。作用机制检验表明,在经济增长对森林破碎化产生影响的路径中,交通基础设施建设存在显著的中介作用,其中介程度为23.255%。【结论】经济增长水平的提高对京津冀地区森林破碎化程度的提高具有显著的正向影响。经济增长水平的提高能够有效地促进交通基础设施建设,提高道路的分布密度。交通基础设施的建设对地区森林破碎化程度的加深具有显著的正向影响。在经济增长的过程中将通过交通基础设施建设这一中介要素对森林破碎化产生影响。     

上海地区汉族人单胺氧化酶基因微卫星DNA多态性研究

应用扩增片段长度多态性技术,分析单胺氧化酶基因的ＭＡＯＡ（ＣＡ）。力ＭＡＯＢＩ（ＧＴ）ｎ２个基因座的微卫星ＤＮＡ多态性。在２４６名（男性１２２人,女性１２４人）无血缘关系上海地区汉族人中检出ＭＡＯＡ（ＣＡ）ｎ基因座８－种等位基因（１１０－１２４ｂｐ）和１９种基因型。     

基因工程实验教学改革的实践探索

高等学校如何创新教学模式,理论课和实验课相结合,培养应用型人才,是亟待解决的问题。随着网络信息技术的发展及其在高等学校教学中的应用,为建立虚拟实验室培养应用型人才提供了有力的平台。文中以创建基因工程\"DNA抽提的虚拟实验\"为例,结合电子科技大学中山学院的网络教学资源,系统介绍了建设基因工程虚拟实验的意义、基本思路及设计原则,以期对该环境下的其他课程探索创建虚拟实验提供有益参考。     

基于批分离实验的最大独立集问题DNA算法

根据解决最大独立集问题的需要,讨论了简化的粘贴模型,该模型只由单链DNA的存储链和分离板组成.以分离实验为基础提出了批分离实验和生化操作过程,该实验可以快速分离存储链.基于批分离实验设计了最大独立集问题的DNA算法,并给出其生化实现过程:先形成所有顶点子集的初始解空间;接着用批分离实验对每个顶点进行检测,筛选全部满足不相邻要求的顶点子集,从而得到全部独立集;然后通过电泳实验得到全部最大独立集;最后通过检测实验输出实验结果.讨论并证明了算法的正确性和复杂性,算法的操作次数是线性的,通过仿真实验说明了算法的有效性和可行性.     

Mitochondrial DNA variation analysis suggests extreme low genetic diversity in Guizhou snub-nosed monkeys （Rhinopithecus brelichi）

Guizhou snub-nosed monkey (Rhinopithecus brelichi) is a unique, endangered primate in China, mainly distributed in Fanjing Mountain National Natural Reserve, Guizhou Province, in an area of 275 km2. Recently, habitat loss and fragmentation have caused population isolation. To assess genetic diversity within this species and its population structure, we sequenced 400 bp of the hypervariable I segment from the mitochondrial DNA control region for 128 individuals. Only one haplotype was identified from these individuals. Compared with other primate species, R. brelichi can be regarded as a species with very low genetic diversity, which further adds to the conservation concern.     

Ancient DNA sequences of rice from the low Yangtze reveal significant genotypic divergence

Rice (Oryza sativa) was first domesticated in the lower and middle Yangtze regions of China, and rice remains have been found in many Chinese archaeological sites. Until now, only phenotypic archeobotanical evidence, such as the spikelet bases of ancient grains, has been used to speculate on the domestication process and domestication rate of rice. In this study, we sequenced 4 genomic segments from rice remains in Tianluoshan, a site of the local Hemudu Neolithic culture in the low Yangtze and two other archaeological sites (~2400 and 1200 BC, respectively). We compared our sequences with those of the current domesticated and wild rice (O. rufipogon) populations. At least two genotypes were found in the remains from each site, suggesting a heterozygotic state of the rice seeds. One ancient genotype was not found in the current domesticated population and might have been lost. The rice remains belonged to the japonica group, and most if not all were japonica-type, suggesting that the remains might be at an early stage of indica-japonica divergence or an indica-japonica mixture. We also identified sequences with significant similarity to those from species of Sapindales, Zygophyllales, and Brassicales, which is consistent with the identification of other plant remains in the Tianluoshan site and the common rice field weeds such as mustards in southern China.     

重症急性胰腺炎病人外周血单个核细胞线粒体DNA拷贝数的意义

目的探讨重症急性胰腺炎患者外周血单个核细胞线粒体DNA拷贝数与患者病情严重程度、预后的相关性。方法分离研究对象（重症急性胰腺炎患者34名,健康对照组17名）外周血单个核细胞,采用荧光实时定量PCR检测各组PBMC线粒体DNA相对舍量,其与严重程度、预后的相关性。结果重症急性胰腺炎患者线粒体DNA含量较健康对照组明显降低（P〈0．05）。患者单个核细胞线粒体DNA拷贝教与APACHEⅡ评分呈负相关（r=-0．425）其中并发症组mtDNA拷贝数显著低于无并发症组（P〈0．05）。结论重症急性胰腺炎患者外周血单个核细胞中线粒体DNA含量显著下降,与患者APACHEⅡ评分呈负相关,且低水平的线粒体DNA拷贝数提示并发症发生率的升高,因此,线粒体DNA拷贝数可作为潜在评估患者病情危重程度及预后的指标,这一发现值得进一步大型,前瞻性的研究。