Robustness of the Y STRs DYS19, DYS389 I and II, DYS390 and DYS393: optimization of a PCR pentaplex

Various technical methods were investigated with the aim of developing a multiplex system to amplify five Y-chromosome STR loci in the same PCR reaction: DYS393, DYS19, DYS390, DYS389 I and DYS389 II. A sequenced allelic ladder was constructed with previously sequenced alleles including the most common ones. A number of reamplification conditions of the allelic ladders were tested. The pentaplex was evaluated for typing using two different platforms (ABI and ALF) with promising results. However, in degraded samples non-specific artifacts were observed in the DYS393 system in the same range of sizes as the real alleles. This system can also be typed in females under relatively low stringency conditions in the PCR amplification, making this system prone to errors in critical samples. This lack of specificity can be reduced by increasing the stringency of the PCR conditions. The DYS19 ladder cannot be reamplified as stutters appear after a few reamplifications. These stutters are probably due to a 2 bp slippage induced by the presence of a TA repeat stretch in the PCR amplified fragments. Non-specific products were also noted in the DYS389 I and DYS389 II amplification, although out of the range of other alleles in this pentaplex. This newly constructed pentaplex has proved to be very useful in population genetic studies because all five Y STR markers can be loaded in the same lane of a gel with other Y STR singleplex or multiplexes. The usefulness of Y-chromosome STRs in criminal casework is especially evident in analyzing azoospermic individuals.     

Population studies of the Y-chromosome specific polymorphisms DYS19, DYS389 I + II, DYS390 and DYS393 in a western German population (Bonn area).

Population studies were carried out on the Y-specific short tandem repeat (STR) systems DYS19, DYS389I + II, DYS390 and DYS393 in a Western German population sample. Determination of the allele frequencies revealed for all these systems, unimodal distribution. The number of observed alleles varied: five for DYS19, six for DYS390, three for DYS389I, seven for DYS389II and six for DYS393. In 102 unrelated male individuals, 56 different haplotypes were found. The haplotype diversity values were similar to those of other European populations.     

Results of a collaborative study of the EDNAP group regarding the reproducibility and robustness of the Y-chromosome STRs DYS19, DYS389 I and II, DYS390 and DYS393 in a PCR pentaplex format

A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in the frame work of the STADNAP program, i.e. standardization of DNA profiling in Europe, in order to evaluate the performance of a Y-chromosome STR pentaplex, which includes the loci DYS19, DYS389 I and II, DYS390 and DYS393 and to determine whether uniformity of results could be achieved among different European laboratories.Laboratories were asked to analyze the five Y-STRs using singleplex and multiplex conditions in three bloodstains and one mixed stain (95% female and 5% male).All the laboratories reported the same results even for the mixed stain included in the exercise. This demonstrates the reproducibility and robustness of Y-chromosome STR typing even with multiplex formats and proves the usefulness of Y-STR systems for analyzing mixed stains with a male component.A total of 930 male samples from 10 different populations from Europe were also analysed for all the loci included in the pentaplex. Eight of these ten populations also included haplotype data.As for single gene analysis, haplotype diversity was higher in Germany and Italy and lower in Western European countries and Finland.Pairwise haplotype analysis shows the Finnish departure from the rest of the populations and a relatively homogeneity in the other European populations with F(ST) estimates lower than 0.05.UPGMA analysis shows an association of Western European population (Ireland, UK, Portugal and Galicia) on the one hand and central European populations on the other.     

DYS19、DYS391、DYS439三个Y-STR荧光标记复合扩增的法医学应用研究

目的　研究Y—染色体STR基因座在法医学检测中的应用价值。方法　用荧光标记DYS19,DYS391,DYS4 39三个Y—STR基因座 ,PCR复合扩增 ,通过毛细管电泳得到结果。结果　三个Y—STR基因座有较高的种属特异性 ;观察 5 0次男性配子细胞形成过程中的减数分裂未发现突变基因 ;对男∶女不同比例混合血样检测 ,当男∶女性血样比达 1∶5 0时 ,仍能准确分型Y—STR基因型 ,并且Y—STR检验较常染色体STR分型更有优势 ;检测了 1～ 15个月病理石蜡切片 ,表明Y -STR基因座适合降解DNA的检测。结论　Y -STR分型适合日常法医检案的需要 ,该方法是对常染色体STR应用的一个补充。     

Results of the GEP-ISFG collaborative study on two Y-STRs tetraplexes: GEPY I (DYS461, GATA C4, DYS437 and DYS438) and GEPY II (DYS460, GATA A10, GATA H4 and DYS439)

A collaborative exercise was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) in order to evaluate the performance of two Y-chromosome STR PCR tetraplexes, which include the loci DYS461, GATA C4, DYS437 and DYS438 (GEPY I), and DYS460, GATA A10, GATA H4 and DYS439 (GEPY II). The participating laboratories were asked to type three samples for the eight markers, using a specific amplification protocol. In addition, two control samples, with known haplotypes, were provided. The results obtained by the 13 different participating laboratories were identical, except for two laboratories that failed to type correctly the same two samples for GATA C4. By sequence analyses, two different GATA C4 allele structures were found. One control sample (allele 21) and two questioned samples (allele 22, correctly typed by all the laboratories, and allele 25) presented the following repeat structure: (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)n, but different from the one found for allele 26 in one sample included in this exercise, as well as in the second control sample (allele 23), namely (TCTA)4(TGTA)2(TCTA)2(TGTA)2(TCTA)2(TGTA)2(TCTA)n. The collaborative exercise results proved that both Y-tetraplexes produce good amplification results, with the advantage of being efficiently typed using different separation and detection methodologies. However, since GATA C4 repeat presents a complex structure, with alleles differing in sequence structure, efficient denaturing conditions should be followed in order to avoid typing errors due to sizing problems.     

DYS393多态性分析及其法医学应用

探讨了Y-DNASTR基因座DYS393的多态性及其法医学应用价值,用变性PAGE结合荧光DNA自动测序仪分析及非变性PAGE,结合银染显示两种PCR扩增产物的方法,并调查了广州地区120例汉族无关男性个体DYS393等位基因分布状况;在此基础上,建立了DYS393和HumARA两基因座的复合扩增体系,结果显示DYS393基因座共检出4种等位基因,复合扩增体系可同时提供性别鉴定和个体识别的信息.     

A novel multiplex PCR system consisting of Y-STRs DYS441, DYS442, DYS443, DYS444, and DYS445

We have developed a new sensitive multiplex PCR system consisting of five male-specific and polymorphic tetranucleotide STRs--DYS441 (GDB: 10013873), DYS442 (GDB: 10030304), DYS443 (GDB: 10807127), DYS444 (GDB: 10807128), and DYS445 (GDB: 10807129) on the Y chromosome. Fifty pg DNA per 10 microL reaction volume was required for the correct typing of five STRs. Using this system, the five Y-STRs were correctly typed from blood and semen stains that had been stored for several years at room temperature.     

Prosecuting sexual assault: A comparison of charging decisions in sexual assault cases involving strangers,acquaintances, and intimate partners

In this study of prosecutors' charging decisions in sexual assault cases, we test the hypothesis that the effect of victim characteristics is conditioned by the relationship between the victim and the suspect. We categorize the victim/suspect relationship as one involving strangers, acquaintances/relatives, or intimate partners, and we examine the effect of victim, suspect, and case characteristics on charging decisions in each type of case. The results of our analysis reveal that the effect of victim characteristics, with one exception, is confined to cases involving acquaintances and intimate partners. In these types of cases, prosecutors were less likely to file charges if there were questions about the victim's character or behavior at the time of the incident. In contrast, the victim's reputation and behavior did not affect charging in cases involving strangers; in those types of cases, prosecutors were more likely to file charges if the suspect used a gun or knife or if the victim was white. We conclude that stereotypes of “real rapes” and “genuine victims” continue to influence the charging decision in at least some types of sexual assault cases.     

DYS391、DYS393基因座X染色体扩增对法医鉴定影响的探讨

目的探讨提高DYS391和DYS393基因座特异性扩增方法及两基因座的X染色体扩增产物对法医学鉴定结论的影响。方法DYS391和DYS393基因座采用PCR扩增、聚丙烯酰胺凝胶电泳结合银染进行分析。结果稀释模板DNA浓度和提高退火温度对提高此两Y染色体基因座特异性扩增并不明显。DYS391和DYS393的X染色体扩增产物对法医学鉴定结论有误导可能性。结论在法医学鉴定尤其是性别鉴定中应谨慎应用DYS391和DYS393基因座。     

Extreme cases and the criminal justice system: responses to a traumatic sexual assault in India

ABSTRACT

This paper addresses criminal justice responses that came on the heels of a traumatic sexual assault in public space in India. The incident referred to as “Nirbhaya,” drew attention to the nation as well as the world the violence against women who on the one hand find themselves in public spaces designed for all denizens in this globalised world, yet, subject to sexploitation and devoid of safeguards and equal protection. In this paper we catalogue modifications to Indian criminal justice as a result of the Nirbhaya case to illustrate how extreme events help drive changes to the system in a large democracy, yet an economically developing one. More specifically, we address changes that have been incorporated in criminal laws, police procedures, and crime prevention efforts, as well as assess the degree to which these efforts have been effective.     

The sexual assault of undergraduate women at historically Black colleges and universities (HBCUs)

Although research has shown that undergraduate women are at high risk for experiencing sexual assault, little research has been conducted with undergraduate women who are attending a historically Black college or university (HBCU). The purpose of this research is to document the prevalence of different types of sexual assault among undergraduate women at HBCUs and make comparisons to data collected from undergraduate women at non-HBCUs. Data on sexual assault victimization were collected from 3,951 undergraduate women at HBCUs using a cross-sectional, web-based survey. These data are compared to data collected from 5,446 undergraduate women at non-HBCUs using the same research methods. Findings indicate that approximately 9.7% of undergraduate women at HBCUs report experiencing a completed sexual assault since entering college. This rate is considerably lower than the comparable rate obtained from undergraduate women at non-HBCUs (13.7%). This difference seems to be associated with differences in alcohol-use frequency. Perhaps undergraduate women at HBCUs drink alcohol much less frequently and are thus less likely to be sexually assaulted when they are incapacitated and unable to provide consent. Alcohol use frequency, while controlling for other factors, seems to have an independent association with the likelihood of an undergraduate woman being sexually assaulted. Implications for the creation and delivery of sexual assault risk reduction and prevention policies and programs are discussed.