隋代鲜卑遗骨反映的拓跋部起源

北魏皇族后裔元威的父系遗传单倍型为C3b-F1756,是一种高频分布于外贝加尔- 蒙古高原东部的遗传类型。考虑到拓跋鲜卑部众在颅骨形态特征以及母系遗传关系上与蒙古人种北亚类型居民也有密切的亲缘关系,研究认为拓跋部起源于外贝加尔- 蒙古高原东部地区。这点由松嫩平原土著考古文化和居民类型在东汉时发生的巨大变化也能体现,这一变化与外贝加尔地区居民南下有关,其主体人群极有可能就是史书所记载的鲜卑。对于学界主流的“拓跋鲜卑嘎仙洞起源说”,因该遗址不像周边任何一种考古文化的发源地,加上其被“发现”的过程疑点重重,因而认为“嘎仙洞”不大可能是拓跋部发源地,拓跋部的兴起与北亚人群从外贝加尔地区南下呼伦湖的迁徙有关。     

交河矿城古车师人的线粒体DNA分析

从距今2000－2500年左右的交河故城古代中提取古DNA，用4对重叠引物对线粒体基因组的调控区(363bp)进行了扩增及测序，线粒体基因组编码区的扩增片段用于限制性片段多样性分析。结果显示4个个体中具有3个DNA序列，其中来自不同墓穴的两个个体的序列相同，说明这两者间有密切的母系遗传关系。系统发育分析表明古车师的4个个体分散分布在现代新疆维吾尔人的序列之中。从这些结果可以初步得出结论，即古车师人群并不是一个同源群体，在早期铁器时代，欧亚人群的混合就已经存在了。     

交河故城古车师人的线粒体DNA分析

从距今2000～2500年左右的交河故城古代人骨中提取古DNA,用4对重叠引物对线粒体基因组的调控区(363bp)进行了扩增及测序.线粒体基因组编码区的扩增片段用于限制性片段多样性分析.结果显示4个个体中具有3个DNA序列,其中来自不同墓穴的两个个体的序列相同,说明这两者间有密切的母系遗传关系.系统发育分析表明古车师的这4个个体分散分布在现代新疆维吾尔人的序列之中.从这些结果可以初步得出结论,即古车师人群并不是一个同源群体,在早期铁器时代,欧亚人群的混合就已经存在了.     

语言与基因：论南岛语族的起源与扩散

南岛语族的起源与扩散问题在语言学、考古学等相关领域一直是个具有争议性的重大理论问题。语言和基因演变的相关性,是语言学和分子人类学的研究领域之一。本文从理论、方法以及材料的角度,梳理了历史语言学视角下南岛语族起源与扩散问题的不同假说,并评述了前人时贤的研究成果及局限性。并在此基础上尝试从跨学科协作角度,结合遗传学、分子人类学最新的研究成果,提出对南岛语族起源与扩散问题的新思考。侗台−南岛语人群的先民可追溯到大陆华南地区,在距今5000−6000年前,开始对外迁移与扩散,其中一支向东迁徙至台湾,经菲律宾、印度尼西亚东部后扩散至远大洋洲,产生了早期Lapita文化;另一支向西,经由中南半岛、东南亚岛屿走廊后迁徙至印度尼西亚东部。现今的东南亚诸多族群是以上两组人群与操巴布亚语的土著人群混合而成的。而留在华南地区的演化为侗台语族等,侗台人群又与南下的北方汉族混合形成了南方汉族。     

有一未配对残基T的DNA [d(TCGCGCG)]_2结构特征的NMR研究

具有交替的嘧啶-嘌呤序列和5′端有一未配对残基T的DNA七聚体[d(TCGCGCG)]_2可以作为研究DNA双螺旋的双链-单链联结构象特征的模本。DNA的这种联结方式存在于它们的复制和转录过程中。用NOESY和TOCSY/HOHAHA实验对其共振峰作了指定。对七个不同混合时间的NOE强度进行了定量分析,用双自旋近似法计算了质子间的距离,揭示了这个分子中令人感兴趣的结构特征。用P.E.COSY实验测定了该DNA双螺旋各糖质子间偶合常数,鉴定了各糖的构象。从而获得了该DNA七聚体在溶液中的结构特征。就整体结构而言,该DNA分子仍属B族DNA,但结构有了很大变化,特别是在端基区。未配对的残基具有不同寻常的顺式构象。为DNA双链-单链联结部分构象提供了有用的借鉴。     

采用电活性标记物N-(2-乙基-二茂铁)马来酰亚胺检测与表面固定的 一致性双链DNA特异性作用的p53蛋白质

建立了电化学检测表面固定捕获的野生型p53蛋白质的方法. 首先在金电极表面形成巯基化的单链DNA探针/己硫醇(HT)混合自组装膜, 随后巯基化的单链DNA探针与溶液中序列匹配的靶点DNA杂交, 所形成的一致性双链DNA捕获溶液中的野生型p53蛋白质. p53分子表面的半胱氨酸残基采用巯基特异性试剂N-(2-乙基-二茂铁)马来酰亚胺(Fc-Mi)进行衍生. 通过检测二茂铁的电化学信号来指示p53与一致性双链DNA之间的特异性相互作用. p53蛋白质与双链DNA的键合程度取决于双链DNA的序列. 该方法可检测的p53最低浓度为1.33 nmol•L－1.     

DNA甲基化检测研究进展

DNA甲基化可以在不改变DNA碱基序列的情况下改变基因活动和功能,影响基因印迹、细胞分化、细胞增殖、染色质重塑、胚胎发育等重要生命活动,是表观遗传的研究重点和热点。为了研究DNA甲基化的分布、状态以及调控机制,越来越多的DNA甲基化分析和检测技术已被开发。本文归纳了近年来的DNA甲基化检测方法,讨论了不同方法的优缺点,为未来深入研究DNA甲基化提供参考。     

基于电中性锇配合物的低背景DNA电化学传感器

采用紫外光谱和电化学方法研究了一种电中性锇配合物Os(DPPZ)(PC)(H₂O)DPPZ=联吡啶并[3,2-a,2',3'-c]吩嗪, PC=2,6-吡啶二羧酸}与DNA的相互作用. 紫外光谱结果表明, DNA的加入引起配合物特征吸收峰的减色及红移效应, 说明二者之间存在嵌插作用. 循环伏安实验结果表明, 配合物溶液中加入DNA后, 氧化还原峰电流降低且式电位正移, 证实了二者之间的嵌插作用模式. 将该配合物作为杂交指示剂对CaMV35S启动子基因片段进行检测发现, 在单链探针DNA修饰电极上未观察到指示剂的电化学信号, 而在杂交后的双链DNA电极上呈现灵敏的电化学响应, 表明传感器具有较高的信噪比. 定量分析实验结果表明, 在最佳条件下, 杂交指示剂在传感器上的还原峰电流与目标序列浓度在8.0×10^-10~2.8×10^-9 mol/L范围内呈良好的线性关系. 选择性实验结果表明, 该传感器对互补序列、碱基错配序列和非互补序列具有良好的识别能力.     

虾夷马粪海胆微卫星标记制备及对3个养殖群体的遗传多样性分析

通过磁珠富集法分离获得了虾夷马粪海胆微卫星DNA序列160个.其中完美型108个(67.50%),非完美型33个(20.63%),复合型19个(11.88%),微卫星DNA序列最多重复次数达到107次.根据这些微卫星DNA序列的两翼序列,采用Primer 5软件设计出虾夷马粪海胆的微卫星引物,通过筛选,采用其中的12对微卫星DNA标记对大连凌水群体(DL)、大连獐子岛群体(DZ)、山东荣城群体(SR)3个虾夷马粪海胆养殖群体的遗传多样性进行分析,共获得73个等位基因,不同引物获得的等位基因数为1~11个,片段大小为84~362 bp.除SUX001位点外,其余位点的PIC值在0.264 0~0.670 5之间,3个群体的平均观测杂合度分别为0.4618(DL),0.437 5(SR)和0.434 0(DZ),平均期望杂合度分别为0.502 6(DL),0.507 9(SR)和0.449 4(DZ).Hardy-Weinberg平衡分析显示,73%的被检测位点显著偏离平衡,F-检验显示4个位点的Fst值低于0.05,表明群体间存在一定程度的分化.群体间遗传相似性系数、遗传距离及UPGMA聚类分析表明大连獐子岛群体(DZ)与大连凌水群体(DL)群体亲缘关系较近,二者与山东荣成群体(SR)亲缘关系较远.对深入了解我国虾夷马粪海胆养殖群体遗传结构特征及其种质资源状况具有重要意义.     

类胶原多肽-DNA共聚序列自组装制备类核蛋白纳米粒子

尽管目前已有大量对自组装及生物纳米材料研究的报道,但大多数关于自下而上自组装的纳米结构仅使用1种类型的结构单元,这限制了结构和功能的多样性.受到核酸与蛋白组装成核蛋白的启发,我们设计了DNA与多肽的共聚序列,利用这2类大分子自组装时天然存在的正交性,可构建更为复杂的超分子自组装体系.研究了炔丙基甘氨酸修饰的类胶原肽pra(POG)_8通过一价铜离子催化的叠氮-炔基环加成(CuAAC)点击化学,分别成功地与2条碱基互补的DNA单链偶联,产生2种CMP-DNA共聚序列,并由变性聚丙烯酰胺凝胶电泳纯化.这2种CMP-DNA共聚序列先分别在4℃静置,由圆二色谱表征确定(POG)_8形成三股螺旋后1∶1等体积混合,促进2条DNA序列相互结合,从而形成超分子自组装的CMPDNA共聚序列.经原子力显微镜和透射电子显微镜表征,该共聚物形成了直径约为25nm、尺寸均一的纳米粒子.在目前为数不多的CMP-DNA共聚序列正交自组装研究中,该实验结果有助于人们探索自然界中多组分系统的自组装行为.     

Analysis of Mitochondrial DNA from the Ancient Tombs of Turfan

IntroductionIn general,inferences aboutpopulation historyare drawn from the studies of genetic diversity incontemporary populations.However,the retrievalof ancient DNA from archaeological remains holdsthe promise to add a temporal component to suchstudies. With the invention of polymerase chairreaction(PCR) ,significant amounts of geneticinformation can be recovered from ancient relic.The analysis of DNA from ancient bones can giveimportant implication for anthropology,archaeology and mole…     

Genetic Structure Analysis of Human Remains from Khitan Noble Necropolis

IntroductionInformation provided by ancient mitochondrialDNA(mtDNA)has been regarded as one of the mostpowerful tools for understanding and reconstructing thepast from the genetic perspective[1].In recent years,molecular studies have been widely employed …     

Phylogenetic Analysis of mtDNA from the Ancient Human of Yuan Dynasty in Inner Mongolia in China

Introduction TheabilitytoextractandanalyzeDNAfrom ancientremainshasarelativelyshorthistory.Early ancientDNA(aDNA)studiesconcentratedonitsnature ofphysicsandchemistryincludingdegradation,frag mentationandoxidationduringlongpreservation.The fieldwasrevoluti…     

Forensic efficacy evaluation and genetic structure exploration of the Yunnan Miao group by a multiplex InDel panel

The aim of the study was to better understand the genetic characteristics of the Miao group in China. Herein, genetic characteristics and forensic application values of 57 autosomal insertion–deletion (InDel) loci were investigated in 210 unrelated healthy individuals from the Chinese Yunnan Miao (YM) group. Meanwhile, the genetic differences in these InDels were compared among the YM group and 26 reference populations. The results of forensic statistical analyses showed that all 57 autosomal InDels were in accordance with the Hardy–Weinberg and linkage equilibria of pairwise loci in the Chinese YM group. Moreover, the combined probability of discrimination and probability of exclusion in the YM group were 0.9999999999999999999999801 and 0.999928, respectively, which indicated that the multiplex amplification including 57 autosomal InDels was suitable for forensic individual identification and paternity testing in the Chinese YM group. In addition, the results of allelic frequency distribution differential analyses, principal component analyses, phylogenetic tree reconstruction, and genetic structure analyses between the Chinese YM group and 26 reference populations revealed that the genetic similarities between the YM group and East Asian populations were more than that between the YM group and other geographical populations. This 57 autosomal InDels system can also effectively distinguish East Asian, European, and African populations.     

Mutation scanning for sequence variation in three mitochondrial DNA regions for members of the Contracaecum osculatum (Nematoda: Ascaridoidea) complex

Anisakid nematodes of seals from different geographical origins, previously identified by multilocus enzyme electrophoresis as Contracaecum osculatum A (CoA), C. osculatum B (CoB), C. osculatum C (CoC), C. osculatum D (CoD), C. osculatum E (CoE) and C. osculatum baicalensis (Cob), were characterised genetically using a mutation scanning approach, in order to define genetic markers for their specific identification and differentiation. Three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit I (COI), and the small and large subunits of rRNA (ssrRNA and IsrRNA, respectively) were amplified separately from individual nematodes by polymerase chain reaction (PCR), analysed by single-strand conformation polymorphism (SSCP), and samples displaying sequence variability were subjected to sequencing. Forty-six haplotypes were defined for 62-66 individuals (representing the six members of C. osculatum). All taxa except CoD and CoE could be identified, or delineated from one another, by nucleotide differences in the COI, ssrRNA and/or IsrRNA sequences. For all three mtDNA regions, 4 (10.5%), 7 (18.4%), 15 (39.5%) and 11 (28.9%) of 38 nucleotide positions were considered diagnostic (fixed) and could thus unequivocally delineate CoA, CoB, CoC and Cob. The lack of an unequivocal nucleotide difference in any of the three mtDNA sequences between CoD and CoE was in accordance with previous ribosomal DNA sequence data but inconsistent with multilocus enzyme electrophoretic data. Using all fixed nucleotide positions, CoA, CoD/E and CoB were genetically more similar to Cob than each was to CoC, similar to previous findings. In spite of not being able to distinguish among all six taxa of C. osculatum, the present study demonstrated clearly the usefulness and attributes of the mutation scanning approach for investigating population genetic structures of species of parasitic nematodes.     

Single nucleotide polymorphisms of mitochondrial DNA HVS‐I and HVS‐II in Chinese Bai ethnic group

For forensic and population genetic purposes, a total of 125 unrelated volunteers’ blood samples were collected from Chinese Bai ethnic minority group to analyze sequence variation of two hypervariable segments (HVS‐I and HVS‐II) in the mitochondrial DNA control region. Comparing the HVS‐I and HVS‐II sequences of the 125 Chinese Bais to the Anderson reference sequence, we found 86 polymorphic loci in HVS‐I and 40 in HVS‐II in mitochondrial DNA sequences of the Chinese Bai ethnic minority group, which defined 93 and 53 different haplotypes, respectively. Haplotype diversity and the mean pairwise differences were 0.992 ± 0.003 and 6.553 in HVS‐I, and 0.877 ± 0.027 and 2.407 in HVS‐II, respectively. We defined four macrohaplogroups R, M, N and D with the proportions ranging from 9.6% to 40.0%. With the analysis of the hypervariable domain from nucleotide 16 180–16 193 in HVS‐I, our study revealed new haplotypes of sequence variations. In addition, the Fst metric, phylogenetic tree, and principal component analysis demonstrated a close genetic relationship between the Bai group and Chinese Han populations from South China, Changsha, and Guangdong. The results support that the Bai group is a multiorigin ethnic minority that has merged with the Chinese Han population.     

Multiplex primer extension analysis for rapid detection of major European mitochondrial haplogroups

The evolution of the human mitochondrial genome is reflected in the existence of ethnically distinct lineages or haplogroups. Alterations of mitochondrial DNA (mtDNA) have been instrumental in studies of human phylogeny, in population genetics, and in molecular medicine to link pathological mutations to a variety of human diseases of complex etiology. For each of these applications, rapid and cost effective assays for mtDNA haplogrouping are invaluable. Here we describe a hierarchical system for mtDNA haplogrouping that combines multiplex PCR amplifications, multiplex single-base primer extensions, and CE for analyzing ten haplogroup-diagnostic mitochondrial single nucleotide polymorphisms. Using this rapid and cost-effective mtDNA genotyping method, we were able to show that within a large, randomly selected cohort of healthy Austrians (n = 1172), mtDNAs could be assigned to all nine major European haplogroups. Forty-four percent belonged to haplogroup H, the most frequent haplogroup in European Caucasian populations. The other major haplogroups identified were U (15.4%), J (11.8%), T (8.2%) and K (5.1%). The frequencies of haplogroups in Austria is within the range observed for other European countries. Our method may be suitable for mitochondrial genotyping of samples from large-scale epidemiology studies and for identifying markers of genetic susceptibility.     

Genetic evidence of an Asian background in heteroplasmic Iberian cattle (Bos taurus): effect on food authentication studies based on polymerase chain reaction-restriction fragment length polymorphism analysis

This work was aimed at identifying nucleotide polymorphic sites in a 359 bp region of the cytochrome b (cytb) mitochondrial gene of Iberian cattle (Bos taurus). This region is widely used as target in polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) species identification studies in foodstuffs destined for human and animal consumption. Two different coexisting restriction patterns were observed in four of the six animals studied when the 359 bp DNA fragment was cleaved with PalI, HinfI, MvaI, RsaI, or MboI. The amplification of both genotypes with the mitochondrial-specific primers L14735 and H15149 revealed the absence of nuclear pseudo-cytb genes, confirming the existence of mitochondrial heteroplasmy. The two coexisting mtDNA fragments were selectively sequenced in PCR extracts in which one genotype predominated over the other, both exhibiting a sequence variation of 10.4%. From the 37 nucleotide mismatches observed between genotypes, 32 were transitions and five were transversions. While 31 of the nucleotide mismatches between genotypes resulted to be conservative at the amino acid level, six changes implied amino acid substitutions, five of them being located in the variable transmembrane region. Genetic analysis suggests the presence of an Asian background in the mitochondria of Iberian cattle: while one of the genotypes matched the published sequence for Bos taurus, the other genotype clustered with a B. primigenius indicus animal and close to an Asian Bos taurus animal. These results also suggest that a number of current PCR-RFLP species identification methods based on cytb sequences may not be reliable for the accurate detection and identification of bovine material: an alternative battery of enzymes consisting of MmeI, NlaIV, and AluI is proposed.     

Usefulness of microchip electrophoresis for the analysis of mitochondrial DNA in forensic and ancient DNA studies

We evaluate the usefulness of a commercially available microchip CE (MCE) device in different genetic identification studies performed with mitochondrial DNA (mtDNA) targets, including the haplotype analysis of HVR1 and HVR2 and the study of interspecies diversity of cytochrome b (Cyt b) and 16S ribosomal RNA (16S rRNA) mitochondrial genes in forensic and ancient DNA samples. The MCE commercial system tested in this study proved to be a fast and sensitive detection method of length heteroplasmy in cytosine stretches produced by 16 189T>C transitions in HVR1 and by 309.1 and 309.2 C-insertions in HVR2. Moreover, the quantitative analysis of PCR amplicons performed by LIF allowed normalizing the amplicon input in the sequencing reactions, improving the overall quality of sequence data. These quantitative data in combination with the quantification of genomic mtDNA by real-time PCR has been successfully used to evaluate the PCR efficiency and detection limit of full sequencing methods of different mtDNA targets. The quantification of amplicons also provided a method for the rapid evaluation of PCR efficiency of multiplex-PCR versus singleplex-PCR to amplify short HV1 amplicons (around 100 bp) from severely degraded ancient DNA samples. The combination of human-specific (Cyt b) and universal (16S rRNA) mtDNA primer sets in a single PCR reaction followed by MCE detection offers a very rapid and simple screening test to differentiate between human and nonhuman hair forensic samples. This method was also very efficient with degraded DNA templates from forensic hair and bone samples, because of its applicability to detect small amplicon sizes. Future possibilities of MCE in forensic DNA typing, including nuclear STRs and SNP profiling are suggested.