MALDI-TOF-MS对Y染色体上66个二等位基因的检测

目的分析华东地区汉族人群Y染色体上66个二等位基因遗传标记的多态性,并评价其法医学应用价值。方法采用多重PCR联合基质辅助激光解吸/电离-飞行时间质谱(matrix-assisted laser desorption/ionization time-of-flight mass spectrometry,MALDI-TOF-MS)技术对华东地区205名汉族男性无关个体Y染色体上66个二等位基因遗传标记进行分型研究,使用直接计数法统计待测位点的等位基因频率,用公式计算基因多样性和单倍型多样性,用Arlequin v3.5.2.2软件检测该体系的单倍型并且进行群体遗传学比较。结果其中60个二等位基因遗传标记在华东地区汉族男性人群中呈多态性分布,基因多样性为0.0385~0.501 9,共检测到85种单倍型,单倍型多样性为0.970 3。部分SNP位点的等位基因分布在华东地区汉族人群和新疆汉族人群、广东汉族人群差异具有统计学意义。结论 60个二等位基因遗传标记及其检测体系在亲权鉴定和个体识别中可补充提供遗传信息,MALDI-TOF-MS技术可以进行二等位基因遗传标记的分型检测。     

荧光复合扩增4个Y染色体STR的单倍型及其法医学应用

目的建立一套Y染色体STR的双色荧光复合扩增系统,调查4个Y-STR基因座单倍型分布情况及其在混合斑物证检验中的法医学应用前景。方法荧光标记引物复合扩增Y-GATA-A10、DYS531、DYS557和DYS448四个Y染色体特异性STR基因座,并用ABⅠ310遗传分析仪对扩增产物进行检测、分型。结果在成都汉族120名无关男性个体中,四个基因座分别检出5、5、8、7个等位基因,共检出78种单倍型,单倍型基因多样性为0.9881。对3例本教研室不能用常规常染色体STR对男性成份作出同一认定的混合斑检材,该系统成功的作出了与嫌疑人血液Y-STR基因型一致的鉴定结论。结论建立的Y-STR荧光标记复合扩增系统具有很高的识别能力,对建立Y染色体STR数据库,研究群体遗传学和进行法医学混合斑物证鉴定有重要意义。     

性染色体及线粒体DNA遗传标记的法医学应用

对性染色体及线粒体DNA的结构特征、遗传特征等相关基础知识及其遗传标记在法医学领域应用的研究进展等进行了综述,分析了上述各类遗传标记在法医学领域应用的利弊,以促进非常染色体DNA遗传标记在法医学实践中的应用。     

6个X-STR基因座的连锁不平衡和单倍型分析

X染色体遗传标记具有特殊的遗传特点,使其成为亲权鉴定重要的辅助遗传标记[1-2],尤其是在祖母-孙女等亲权关系的鉴定。部分紧密连锁的X染色体短串联重复序列（X,X-STR）呈连锁遗传;因此XSTR检验时,既要考虑基因座间的连锁关系,也要考虑不同等位基因间的连锁不平衡状态。本研究分析Xq21、26区6个X-STR基因座（DXS10101、HPRTB、DXS10103、DXS6799、DXS6789、DXS6801）的连锁不平衡状态及其单倍型分布,为法医学应用提供基础。     

山西汉族X-STR基因座DXS9902、DXS7132的遗传多态性

X染色体STR基因座由于其独特的遗传方式,在法医学鉴定的一些特殊案件中表现出了常染色体遗传标记无法比拟的优势,已有多个X染色体的STR基因座被应用于法医学鉴定。本研究通过对山西汉族人群DXS9902和DXS7132两个X-STR基因座及单倍型遗传多态性进行调查,为法医学个体识别、亲子鉴定及遗传学研究等提供了基础数据。     

闽南地区汉族17个Y-STR基因座遗传多态性

正在法医遗传学研究领域,Y染色体遗传标记已成为常染色体的重要辅助遗传标记。由于Y染色体遗传标记的遗传特点和在不同群体中的差异,其单倍型的分布具有群体特异性。本研究对中国闽南地区汉族17个Y-STR基因座和单倍型频率的遗传多态性进行调查,旨在为人类遗传学、法医遗传学研究提供群体遗传学数据。     

X—STR基因座的法医学应用研究进展

对X染色体的结构特征、遗传特征及其短串联重复序列（STR）基因座在法医学领域的研究历史、现状进行了综述。并分析了X染色体STR基因座在混合斑鉴定和复杂亲子关系鉴定中的应用,以及在法医学领域应用中应注意的问题．如单倍型和连锁不平衡现象等。     

4个Y-STR基因座遗传多态性及分子克隆技术制备分型标准物

目的研究Y染色体4个新发现的STR基因座在成都汉族群体中的遗传多态性,寻找适合于法医学应用的Y-STR基因座并用分子克隆法制备其等位基因分型标准物。方法用PCR扩增和非变性聚丙烯酰胺凝胶电泳技术,对105名成都地区汉族无血缘关系男性个体的4个Y-STR基因座进行分型。并通过分子克隆技术制备DYS643基因座的等位基因分型标准物。结果DYS632、DYS634、DYS642和DYS643四个STR基因座均具有Y染色体特异性,在成都汉族群体中等位基因个数分别为2、4、3和5,共检测出31种单倍型;DYS643基因座的等位基因分型标准物可以用于群体研究。结论DYS643基因座及其分子克隆法制备的等位基因分型标准物具有较高的法医学应用价值。     

SNP分型方法及在法医学等领域的应用

随着单倍型图的产生,SNP越来越受到关注。不仅仅在Y染色体和线粒体,常染色体和X染色体上的SNPs的应用潜能也将被发现。SNPs具有比较低的突变率和适合于降解DNA分析的特点,在法医学领域也受到关注。本文综合介绍了SNPs和X-SNPs的一般特性、分型方法及其在法医学的应用。     

武汉汉族8个Y染色体双等位基因标记遗传多态性

目的筛选汉族群体中具有多态性的Y染色体双等位基因标记并研究其等位基因及单体群频率分布, 为法医学应用和群体进化研究提供基础数据。方法采用片段长度差异等位基因特异性PCR和PAGE技术对武汉地区160名男性汉族无关个体的8个Y染色体双等位基因标记(M9、M89、M111、M119、M122、M134、IMS-JST003305 和SRY+465)进行分型。结果 8个双等位基因标记在武汉汉族群体中均具有遗传多态性,其基因多样性(GD)范围为 0．0126-0．4830,共检出9种不同单体群(Hg1～9),其单体群多样性(HD)为0．7776。结论 8个Y染色体双等位基因标记组成的单体群在法医学应用和群体进化研究中具有一定的实用价值,可作为Y-STRs标记的有效补充。     

Y-chromosome STR haplotype diversity in Brazilian populations

A sample of 198 unrelated males distributed among the five geopolitical regions in Brazil were typed for the minimal Y-STR haplotype composed of microsatellite loci DYS19, DYS385I/II, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393. Gene frequency data, gene diversity, haplotype diversity and power of discrimination were estimated. An AMOVA indicated that 99.97% of the haplotypic variation is found within regions and only a small 0.03% and non significant variation is found among the five regions (Fst=0.00031, P-value=0.43). This result suggests that a single national database of Y-STR haplotypes can be used in the quantitative assessment of matches in forensic casework in the Brazilian population. A significant haplotype diversity of 99.8% was found and 172 different haplotypes were observed in 198 chromosomes. Haplotype (14-11, 14-13-29-24-11-13-13) with five occurrences in 198 chromosomes was the most frequent in Brazil.     

Population data on 11 Y-chromosome STRs from Guiné-Bissau

The forensic value of Y-STR markers in Guiné-Bissau was accessed by typing of 215 males. Allele and haplotype frequencies, determined for loci DYS19, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439 and the duplicated locus DYS385, are within the limits of variation found in other populations south of the Sahara. The level of discrimination achieved is Guineans is higher than for European or other African populations with comparable data. The haplotype diversity of 0.9995 is reduced to 0.9981 when the minimal haplotype is considered thus revealing the importance of increasing the number of typed loci.     

Y-chromosome haplotypes in Italy: the GEFI collaborative database.

A sample of 1176 males from 10 Italian regions have been typed for DYS19, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393, and DYS385. Individual haplotype data are available on line. A low degree of variation is present among regions. Use of this database is specifically recommended for forensic applications in Italy.     

Allele frequencies and population data for 17 Y-chromosome STR loci in a Serbian population sample from Vojvodina province

Seventeen Y-chromosomal STR (short tandem repeat) loci were analyzed in a group of 185 healthy unrelated male individuals (n=185) from the population of Serbian province of Vojvodina. After minimal haplotype STR loci analysis we observed 129 different haplotypes. The most frequent haplotype was found in 13 copies, and total haplotype diversity was 99.11%. After analysis of additional eight Y-STR loci (DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and YGATAH4) there were 176 different haplotypes observed, out of which 168 appeared in single copies, and 7 haplotypes appeared twice. The most frequent haplotype was found in three copies. The haplotype diversity (99.94%) and discrimination capacity (95.13%) were calculated. Comparisons were made with previously published haplotype data on neighbouring population samples and significant differences were demonstrated at DYS19, DYS389II and DYS393 loci. Pairwise comparison of populations revealed that our sample was significantly different only from Hungarian sample (RST=23.98%, p=0.0091).     

Species identification of Kachuga tecta using the cytochrome b gene

A DNA technique has been established for the identification to species level of tortoises. The test on the shell of the animal was used to identify samples from the species Kachuga tecta. A total of 100 tortoise shell specimens collected from the National Council of Agriculture (COA), Taiwan, were used in this study. Primer pairs were designed to amplify partial DNA fragments of cytochrome b within the mitochondrial genome. The DNA data showed that among the 100 samples, there were four distinct haplotype DNA sequences, within which there were a total of 90 variable sites. Between haplotypes I and II, there was only 1 nucleotide difference at position 228. Between haplotypes I and III, 65 nucleotide differences were observed; haplotypes I and IV, 62 nucleotide differences; and haplotypes III and IV, 56 nucleotide differences were observed. There were 66 and 63 nucleotide differences between haplotypes II and III and haplotypes II and IV respectively. All four haplotypes were compared with the DNA sequences held at the GenBank and EMBL databases. The most similar species were K. tecta (haplotype I and II), Morenia ocellata (haplotype III) and Geoclemys hamiltonii (haplotype IV), and their respective mtDNA similarities were 99.5%, 99.3%, 89.9% and 99.5%. However, as haplotype III was only 89.9% homologous with M. ocellata, it would seem that this haplotype shows only a limited relationship with a similar species registered currently in these databases. The method established by this study is an additional method for the identification of samples protected under Convention International Trade in Endangered Species (CITES) and will improve the work for the preservation of the endangered species.     

Forensic evaluation and haplotypes of 19 Y-chromosomal STR loci in Koreans

In this study, 19 Y-specific STR loci (DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS388, DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, DYS446, DYS449, and DYS464) were analyzed in 301 unrelated Korean males by three multiplex PCR systems. The haplotype diversity using the classical set of Y-STRs (DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, and DYS385; multiplex I) was 0.9963. For the same individuals, the haplotype diversity value using the new set of highly informative Y-STRs (DYS385, DYS446, DYS449, and DYS464; multiplex III) was 0.9989, while that using the combined set of Y-STRs by adding DYS388 to the previously studied DYS434, DYS435, DYS436, DYS437, DYS438, and DYS439 (multiplex II) was 0.9509. A total of 297 different haplotypes were identified using the 19 Y-STR markers, of which 293 were unique and 4 were found twice. The overall haplotype diversity was 0.9999. The evaluation of the information of selected markers by combination of each marker with the minimal haplotype showed that DYS434, DYS435, DYS436, DYS437, and DYS438 do not significantly contribute to increment of haplotype diversity. However, respective conjunction of DYS464, DYS449, and DYS446 with the minimal haplotype considerably increased the haplotype diversity. Especially, DYS464 is expected to be the most useful marker that can be included in the expanded minimal haplotype. These results including the haplotype data at 19 Y-STR loci in the present study would provide useful information in forensic practice in a Korean population.     

Y STR haplotype data for New Zealand population groups using the Y-Plex 6 kit

Allele and haplotype frequencies were obtained for the six Y STR loci DYS19, DYS389II, DYS390, DYS391, DYS393 and DYS385 in the New Zealand population. Ninety-two different haplotypes were found. The Maori population had a specific haplotype that occurred in over 30% of the population. The Pacific Island population exhibited a triple repeat at the DYS385 locus in 26% of individuals, something rarely observed in other population groups.     

Y-chromosomal STR haplotypes in a population from the Amazon region, Brazil

Haplotype and allele frequencies of the nine Y-STR (DYS19, DYS389 I, DYS389 II, DYS390, DYS391, DYS392, DYS393, DYS385 I/II) were determined in a population sample of 200 unrelated males from Belém, Brazil. The most common haplotypes are shared by 1.5% of the sample, while 186 haplotypes are unique. The haplotype diversity is 0.9995+/-0.0006. The data obtained were compared to those of other Brazilian populations. AMOVA indicates that 99.91% of all the haplotypical variation is found within geopolitical regions and only 0.09% is found among regions.     

Examination of Y-STR mutations in sex chromosomal abnormality in forensic cases

The Y-STR typing was carried out on eight DNA samples (three from criminal cases) demonstrating Klinefelter's syndrome. STR types in the X chromosome were randomly distributed. However, some Y-STR markers were distributed within the normal range but restricted to only one or two specific alleles, that is, some specific haplotypes were found in Klinefelter's syndrome. In addition, a single nucleotide polymorphism in DYS390 (transversion of G to A at the 28th position downstream of tandem repeats) was detected in Klinefelter samples. This Y-STR polymorphism and restricted Y-STR alleles in Klinefelter's syndrome is not known, but it might be related to the genesis of Klinefelter's syndrome. We also found that extended standard haplotypes of these samples are extremely rare in the normal population, according to the Y-STR haplotype reference database (YHRD). The extended standard haplotype database in a Japanese population is also reported. In 100 unrelated Japanese, 89 haplotypes were observed, and the haplotype diversity was calculated to be 0.9866.