一种简便快捷的植物线粒体质粒DNA的提取方法

介绍了一种从植物材料中提取线粒体质粒DNA的方法,该方法不需要密度梯度离心和有机溶剂油提,整个提取过程可在较短时间内完成,该方法简便,快捷,效果好,对拷贝数低的线粒体质粒DNA得率高。     

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.     

以端粒末端DNAs为靶分子的抗癌药物的研究进展

端粒末端G-四股螺旋DNAs可以抑制端粒酶的键合，进一步抑制癌细胞的生长和大量繁殖。因此，端粒DNAs已成为具有抗癌药物作用的靶分子，能键合并稳定G-四股螺旋DNAs的小分子化合物是潜在的抗肿瘤药物。设计和合成能特异性靶向G-四股螺旋DNAs并显著抑制端粒酶活性的配体成为当今抗癌药物研究的又一大热点。叙述了近年来以端粒G-四股螺旋DNAs为靶分子的抗癌药物设计、合成的最新进展。     

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.     

珍稀濒危鸟类褐马鸡mtDNA的分子克隆及序列分析

利用改进的SDS裂解、氯仿∶异戊醇抽提的方法提取了褐马鸡肌肉基因组DNA,通过PCR扩增的方法特异性扩增了褐马鸡线粒体（mtDNA）控制区（D-loop）全序列片段,PCR产物经凝胶回收纯化后与载体pGEM-TEasy相连,然后转化感受态细胞DH-5α,在含X-gal、IPTG的氨苄LB平板上筛选阳性克隆,重组质粒经PCR和琼脂糖凝胶电泳检测后,对目的片段进行测序.结果表明,经PCR特异性扩增出的褐马鸡线粒体控制区全序列碱基数为1 237 bp,用Blast程序进行检索比较表明此扩增序列与GeneBank中发表的褐马鸡线粒体控制区序列同源性高达99%,且具有鸟类线粒体的标志性序列.