基于微流控芯片的InDel快速族群推断体系研究

目的 QuickTargSeq全集成法医DNA现场快速检测系统是国内首台自主研制的现场快检仪,可应用于InDel族群推断检测,2 h左右完成“样本进-结果出”的快速自动化InDel分型。本文对InDel族群推断微流控芯片检测体系的性能进行评估,以期为实践应用提供参考。方法 使用InDel族群推断微流控芯片检测体系,对体系的灵敏度、干扰物耐受性、成功率、分型准确率、精确性、准确性、峰平衡性及检材适应性进行验证评估,同时对测试样本的族群来源进行推断。结果 138份样本的全集成检测成功率为95.65%,分型准确率为98.85%;DNA模板量≥5 ng时,可获得完整InDel分型,口腔拭子样本最佳采集次数为口腔内壁左右两侧各刮擦8次,血卡样本最佳检测方式为6片（Φ=2 mm）;所有基因座的平均杂合子峰高比值为0.86;10次运行的等位基因分型标准物（allelic ladder）片段大小标准差均在0.3 bp以内,测试样本等位基因和相应的等位基因分型标准物之间的片段准确性均在0.5 bp以内。结论 该体系可实现对口腔拭子、血卡、唾液卡及烟蒂样本的准确分型,能够准确推断样本的族群来源。     

血清中提取DNA进行个人身份识别鉴定

在法医物证学实际案例中,最常见的生物检材是全血、人体组织、毛发、口腔脱落上皮细胞(口腔拭子)等,传统认为血清中没有DNA存在,不能作为法医生物检材应用于法医学实践。本文应用微量的人体血清进行了成功的DNA分型检测,有效的进行了个人身份的识别。现报道如下:     

小尾寒羊五个微卫星基因座遗传多态性研究

小尾寒羊是我国优良的地方绵羊品种,具有极高的繁殖力,平均每胎产羔2．6只。利用与绵羊高繁殖力主效基因Fec^B和FecX^1连锁的5个微卫星标记（OarAE101,BM1329,BMS2508,TGLA54t TGLA68)对244小尾寒羊母羊进行了遗传检测。用非变性（中性）聚丙烯酰胺凝胶电泳检测同卫星的PCR扩增产物,计算了5个同卫星基因座的等位基因频率,多态信息含量,基因纯合度和杂合度。在小尾寒羊中检测到BM1329有6个等位基因,片段大小为160－180bp,164bp等位基因频率最高（0．6320）;检测到OarAE101有9个等位基因,片段大小为97－135bp,97bp等位基因频率最高（0．7930）;检测到TGLA54有5个等位基因,片段大小为116－136bp,134bp等位基因频率最高（0．8500）;检测到TGLA68有2个等位基因,片段大小为98－100bp,2个等位基因频率相近,检测到BMS2508有6个等位基因,片段大小为93－115bp,99bp等位基因频率最高（0．4795）。BM1329,OarAE101,TGLA54,TGLA68,BMS2508的多态信息含量／基因纯合度／杂合度分别为0．4481／0．4840．0．5160,0．3516／0．6375／0．3625,0．2528／0．7326／0．2674,0．3733／0．5034／0．4966,0．5809／0．3581／0．6419。可见BMS2508的遗传变异最大,TGLA54的遗传变异最小。这些结果可为小尾寒羊种质特性研究提供分子基础数据。     

高保真酶特异性检测大鼠SNP基因型新方法

目的应用高保真酶（Pfu）和3’末端修饰引物在单管双向等位基因特异性扩增（SB-ASA）中区分SNP基因型,建立高保真酶特异性检测SNP基因型的新方法。方法选取近交系大鼠SNP位点,以RS8149053为例,设计两个外部引物和两个等位基因特异性引物,四引物3’末端进行硫代磷酸化修饰,应用高保真聚合酶（Pfu）进行特异性扩增,扩增结果测序验证其可靠性。结果在RS8149053 SNP位点（C/T）上,等位基因型CC扩增出179 bp目的片段,基因型TT扩增出597 bp目的片段,基因型不同则扩增出分子量不同的片段,目的条带测序结果与Rat Genome Database数据库基因型结果一致,高保真酶扩增结果稳定且特异性强。结论高保真酶等位基因特异性扩增技术能有效降低假阳性率,是一种快速、特异的SNP基因分型新方法。     

中国南方汉族人群6个Y-STR基因座 遗传多态性及法医学应用

为研究中国南方汉族人群DYS393等6个Y-STR基因座的遗传多态性并用于法医学鉴定,通过采用PCR复合扩增和基因测序仪荧光检测方法,检查204个无关男性个体,调查南方汉族的6个Y-STR基因座的单倍型频率,并对93对真父子和38对非父子的亲子鉴定样本进行检测。结果DYS393基因座检出5个等位基因,DYS19基因座检出6个等位基因,DYS389Ⅱ基因座检出8个等位基因,DYS390基因座检出6个等位基因,DYS391基因座检出4个等位基因,DYS385 基因座检出44个等位基因,共检出176种单倍型。93对真父子中,观察到2例分别有1个基因座突变。检测38对非父子,有1个或2个Y-STR基因座排除的案例各有1例（2.6%）;有3 个和3个以上的Y-STR基因座可以排除父子关系的案例为35例（92.1%）;6个Y-STR基因座不能排除父子关系的为1例。结果表明6个Y-STR基因座具有丰富的遗传多态性,可用于法医学个体识别和亲子鉴定。Abstract: To study the genetic polymorphisms of six Y-chromosome specific STR loci in the southern Chinese Han population and apply it in forensic science, six Y-STR loci were amplified by multiple PCR and the PCR products were detected by using ABI PrismTM 377 Sequencer. The haplotype frequencies at 6 Y-STR loci were determined in a total of 204 unrelated males from southern Han population of China. Ninety-three father/son pairs with demonstrated paternity and thirty-eight non-paternity father/son pairs were detected by using our Y-STR system. As a result, the number of alleles for DYS393、DYS19、DYS389Ⅱ、DYS390、DYS391and DYS385 were 5, 6, 8, 6, 4 and 44 , respectively. A total of 176 haplotypes at 6 Y-STR loci were found. Two father/son pairs with single Y-STR mutation were observed in the 93 father/son pairs with demonstrated paternity. Among the 38 non-paternity father/son pairs, one case with one Y-STR exclusion of paternity, one case with two Y-STR exclusions and 35 cases with 3 or more Y-STR exclusions were observed. Non-exclusion of paternity at 6 Y-STR loci was found only in one case. This result indicated that the six Y-STR loci were highly polymorphic and are suitable for personal identification and paternity testing.     

16个Y-STR基因座快速复合扩增体系的构建研究

为了构建一套16个Y-STR基因座的快速复合扩增体系,用于满足公安的实战时效性需求,文中选择DYS19、DYS385a/b、DYS390、DYS391、DYS392、DYS393、DYS438、DYS439、DYS437、DYS448、DYS456、DYS458、DYS635、Y_GATA H4和DYS447共16个基因座,将Roche FastStart Taq DNA Polymerase体系与ProPlex热循环仪结合,以法医DNA标准品9948为实验模板,从扩增条件、扩增体积、缓冲液选择、DNA聚合酶用量、基因座间的平衡性调整、快速扩增程序的优化等方面进行一系列复合扩增实验,比较不同条件下等位基因的丢失、峰高、基因座间峰的均衡性及非特异峰。结果发现,该快速体系30 min即可获得样本全部16个Y-STR基因座分型,且各等位基因间均衡性良好,无非特异性峰。以上信息初步表明建立的16个Y-STR基因座的快速复合扩增体系可明显提高样品检测效率,对实战中一些时效性案件具有一定的实际意义。     

运用多重PCR-直接测序法检测ABO基因型及其遗传多态性

根据ABO基因座第6和7外显子9个SNP位点设计引物, 复合扩增后直接测序, 根据测序结果判定不同物证检材ABO基因型及其在藏族群体中的多态性分布。成功地检测出经过不同方法处理的血痕、毛发、口腔拭子、骨骼、混合斑等101例腐败、降解及微量检材的ABO基因型, 结果与免疫血清学分型一致, 且该方法具有灵敏度高、特异性好、操作简单、结果准确、客观及能够发现新等位基因等优点。对80名青海藏族无关个体的调查表明, ABO基因型分布符合Hardy-Weinberg平衡, 杂合度H为0.675, 多态信息含量PIC为0.672, 个人识别力DP值为0.874, 非父排除率PE值为0.391, 偶合度I为0.126; 青海藏族ABO等位基因频率O>B>A, 且O等位基因频率高达0.6125。多重PCR-直接测序法检测ABO基因型适用于法医学不同来源的样本, 提高了ABO血型系统的个体识别能力; ABO基因型在青海藏族人群中的分布具有较高多态性, 可用于法医学个体识别及群体遗传学研究。     

微卫星位点DYS19在中国人群中的多态研究

以人DNA为模板,经PCR扩增后,用聚丙烯酰胺凝胶电泳分离扩增片段,再经高灵敏度银染着色,对中国陕西汉族、广东汉族、宁夏回族、辽宁满族、四川彝族、西藏藏族、广西壮族、广西瑶族、新疆维吾尔族、湖南土家族等10个人群535名个体的Y染色体上微卫星位点DYS19的遗传多态性进行了研究。结果表明：中国人群中以等位基因C（194bp）为主要等位基因,基因频率范围在0.25-0.61;等位基因B（190bp）、D（198bp）次之,基因频率范围分别为0.08—0.36、0.06—0.42;而等位基因A（186bp）和E（202bp）频率较低,频率范围分别为0—0.07和0—0.38。在壮族中还检测出了一名携带F（206bp）等位基因的个体。中国人群DYS19等位基因的分布与蒙古人种群体以C型为主的结果相一致。X^2成对比较表明瑶族、藏族与大多数其它中国民族间DYS19表型分布存在差异（P< 0.05）或显著性差异（P< 0.01）。中国人群DYS19的基因频率至今在文献中尚未见报道。     

对法医学相关的DYS549、DYS527和DYS459基因座在男性不育症人群中的缺失、重复调查

位于Y染色体无精症因子区域(Azoospermia factor, AZF)的基因座位点DYS549、DYS527和DYS459在法医学鉴定和家系分析中被广泛应用。但是,在男性不育患者中,DYS549、DYS527和DYS459位点很可能会表现出特殊的基因型,对应用Y染色体短串联重复序列(Y chromosome short tandem repeat, Y-STR)进行个体识别的结果产生干扰。因此,文章应用14个Y-STR基因座复合扩增体系和Y染色体AZFc区DAZ、CDY1基因的拷贝数检测等方法,探讨男性不育症中法医学相关的3个Y-STR基因座的异常分型,对个体识别和家系分析中的DNA检验异常结果提供合理的解释。在240例男性非梗阻性无精、严重少精、先天性双侧输精管缺如(CBVAD)患者中,采用改良的多重PCR体系进行AZF区域微缺失的序列标签位点(Sequence tagged sites, STSs)检测,发现AZF微缺失40例(AZFa：2例;AZFb：2例;AZFc：30例;AZFb+c：6例),AZF的总缺失率为16.67%。应用14 Y-STR复合扩增体系对上述AZF微缺失的阳性患者样本进行检测,发现所有AZFb缺失患者存在DYS549等位基因缺失,AZFc缺失患者存在DYS527、DYS459等位基因缺失,AZFb+c缺失患者存在DYS549、DYS527和DYS459等位基因缺失。在AZF微缺失阴性的不育症患者中,通过检测DAZ、CDY1基因拷贝数发现10例AZFc部分复制的患者(1例为先天性输精管缺如,2例非梗阻性无精症,7例严重少精子症),占所调查不育人群的4.17%。男性不育人群AZF区域3个Y-STR基因座多态性会造成等位基因缺失或者重复,这些异常分型是由于临床遗传缺陷造成的而不是实验偏差。阐明Y-STR在男性不育人群中的异质性可以更好地完善Y-STR数据库和解释STR实验结果。     

西北汉族人群D10S1248、D2S441、D1S1677、D9S1122、D10S1435等5个miniSTR基因座的遗传多态性及其法医学应用

为了调查D10S1248、D2S441、D1S1677、D9S1122、D10S1435等5个miniSTR(mini short tandem repeats)基因座在西北汉族人群中的遗传多态性、遗传稳定性及其在陈旧降解检材中的法医学应用价值, 文章采用荧光PCR和基因分型技术对西北汉族154份无关个体血样、10个家系血液样本及10份陈旧降解检材进行片段长度分析。在西北汉族人群中, 5个miniSTR基因座分别检测出了8、7、7、6、7个等位基因, 等位基因频率分布符合Hardy-Weinberg平衡定律, 杂合度(Heterozygosity, H)为0.662~0.792, 个人识别率(Power of discrimination, PD)为0.869~0.915, 非父排除率(Power of exclusion, PE)为0.382~0.585, 多态信息含量(Polymorphism informa-tion content, PIC)为0.650~0.750。家系和陈旧降解检材的研究表明, 5个miniSTR基因座具有高度的遗传稳定性, 可对陈旧降解检材DNA进行有效的分型。5个miniSTR基因座适合作为西北汉族人群的遗传标记, 用于陈旧降解检材的法医学个人识别和亲权鉴定案件中。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.