Improving the differentiation of closely related males by RMplex analysis of 30 Y-STRs with high mutation rates.

The discovery of rapidly mutating (RM) Y-STRs started to move the field of forensic Y-STR analysis from male lineage identification towards male individual identification. Previously, the forensic value of RM Y-STRs for differentiating male relatives was limited due to the modest number of 13 identified RM Y-STRs. Recently, new RM Y-STRs were discovered, with strong expectations for significantly improving male relative differentiation; however, empirical evidence is missing yet. More recently, the genotyping method RMplex for efficiently analyzing 30 Y-STRs with high mutation rates, including all 26 currently known RM Y-STRs, was introduced. Here, we applied RMplex as well as the current state-of-the-art commercial Y-STR kit: Yfiler™ Plus PCR Amplification kit, to several hundreds of DNA-confirmed father-son pairs. Newly established estimates confirmed the high mutation rates of novel and previous RM Y-STRs. By combining current with previous data, we provide updated consensus estimates of mutation rates for all 49 Y-STRs targeted with both methods. Based on RMplex, 42% of 499 father-son pairs were differentiated, while 14% of 530 pairs based on Yfiler™ Plus, and 48% of 499 pairs based on both methods combined. Regarding brothers, RMplex also clearly outperformed Yfiler™ Plus, with differentiation rates of 62% and 33%, respectively. By combining both methods 72.9% of the brothers showed at least one mutation. For unrelated males, both methods achieved a discrimination capacity of 99.8% and a haplotype diversity of 0.999991, since all males had different haplotypes, except for two, perhaps indicating a hidden paternal relationship. Overall, this study underlines the value of RM Y-STRs in general and RMplex in particular for differentiating male relatives highly relevant in forensic genetics. It provides the first empirical evidence on the high value of RMplex for differentiating close male relatives, which for father-son pairs was almost 60% higher than with the initial set of 13 RM Y-STRs and three times higher than with Yfiler™ Plus. Based on our results from closely related males, we expect RMplex to also improve the differentiation of more distantly related males significantly, which needs empirical demonstration in future studies. We encourage the forensic community to apply RMplex in all forensic cases where a match with a commercial Y-STR kit was obtained between the male suspect and the evidence material, or to solely use RMplex in such cases, aiming to find out if the male suspect or any of his male paternal relatives left the evidence material at the crime scene.

Rudolf Hess - The Doppelgänger conspiracy theory disproved.

The Deputy Führer of the Third Reich Rudolf Hess was captured after a controversial flight to Scotland in 1941. Hess was sentenced to life imprisonment during the Nuremberg War Crimes Trials. He was detained in Berlin's Spandau Prison under the official security designation 'Spandau #7.' Early doubts arose about the true identity of prisoner 'Spandau #7.' This evolved to a frequently espoused conspiracy theory that prisoner 'Spandau #7' was an imposter and not Rudolf Hess. After Hess's reputed 1987 suicide, the family grave became a Neo-Nazi pilgrimage site. In 2011, the grave was abandoned and the family remains cremated. Here we report the forensic DNA analysis of the only known extant DNA sample from prisoner 'Spandau #7' and a match to the Hess male line, thereby refuting the Doppelgänger Theory.

Contamination incidents in the pre-analytical phase of forensic DNA analysis in Austria-Statistics of 17 years.

Forensic DNA analyses have become more and more sensitive in the past years. With the ability to generate DNA profiles even from minute amounts of cellular material also the possibility to detect DNA on trace material that originates from persons not linked to the crime event, such as crime scene investigators, increases. The contamination of crime scene samples can lead to false positive results and misinterpretation that can cause deceptive investigations. In this work we continue a study of 2010 that compared the number of detected contamination incidents that were caused in the pre-analytical phase of forensic DNA analysis with the number of crime scene samples analyzed by our laboratory. Within the past 17 years we were able to detect a total of 347 contamination incidents caused by police officers in approximately 46,000 trace samples to their origin (0.75%). Additionally we demonstrate the usefulness of reference profile databases that contain DNA profiles of police officers to detect contamination incidents of trace material.

Yfiler(®) Plus amplification kit validation and calculation of forensic parameters for two Austrian populations.

With the new 6-dye AmpFISTR(®) Yfiler(®) Plus amplification kit (Thermo Fisher Scientific, Waltham, MA, USA) a set of 25 Y-chromosomal short tandem repeat loci (Y-STRs), including seven rapidly mutating Y-STRs (RM Y-STRs), is now available for forensic DNA typing. In this study we present our validation data for the AmpFISTR(®) Yfiler(®) Plus amplification kit and show the results of Y-chromosomal typing of 425 unrelated male individuals from two Austrian populations (Salzburg and Upper Austria) with the AmpFISTR(®) Yfiler(®) Plus amplification kit. Forensic parameters were calculated and compared for four Y-STR marker sets. We also typed five brother pairs to evaluate the power of discrimination for related individuals. The AmpFISTR(®) Yfiler(®) Plus (Yfiler Plus) kit appeared to be unimpaired by typical inhibitors such as hematin and humic acid or by large amounts of female components. An upgrade of analyzed markers resulted in increased discrimination capacity that is crucial for forensic trace analysis.

Elevated germline mutation rate in teenage fathers.

Men age and die, while cells in their germline are programmed to be immortal. To elucidate how germ cells maintain viable DNA despite increasing parental age, we analysed DNA from 24 097 parents and their children, from Europe, the Middle East and Africa. We chose repetitive microsatellite DNA that mutates (unlike point mutations) only as a result of cellular replication, providing us with a natural 'cell-cycle counter'. We observe, as expected, that the overall mutation rate for fathers is seven times higher than for mothers. Also as expected, mothers have a low and lifelong constant DNA mutation rate. Surprisingly, however, we discover that (i) teenage fathers already set out from a much higher mutation rate than teenage mothers (potentially equivalent to 77-196 male germline cell divisions by puberty); and (ii) ageing men maintain sperm DNA quality similar to that of teenagers, presumably by using fresh batches of stem cells known as 'A-dark spermatogonia'.

An unusual case of identification by DNA analysis of siblings.

A badly decomposed body required identification by means of DNA analysis. A brother and sister of the deceased were available as reference subjects. Although investigation of Y-chromosomal markers established an exclusion condition, autosomal markers suggested a positive identification. In order to increase the reliability of the tests, X-chromosomal markers were also investigated. This analysis showed the body to have an XXY genotype (Klinefelter's syndrome). A number of hypotheses were assessed using biostatistical methods, ultimately resulting in a definite identification. The special aspect of Klinefelter's syndrome proved highly useful for biostatistical analysis.

Characterization of two unusual allele variants at the STR locus ACTBP2 (SE33).

Two uncommon allelic variants have been observed at the locus ACTBP2 (SE33) and both were located far outside the ladder range of commercially available typing kits. The short variant showed a 60-bp deletion upstream of the 5'-flanking region with a typical type I repeat structure, which actually would have to be assigned as allele 16. The long allele revealed a typical type III sequence structure that has to be designated as allele 41.

Ferritin--a mediator of apoptosis?

Previously we have demonstrated an apoptosis inducing activity for a rat hepatocyte conditioned medium (CM) presumably mediated by acidic isoferritins. Here, we present support for this assumption since isoferritins purified from different rat hepatocyte CM significantly enhanced the frequency of apoptotic cells in primary rat hepatocytes, an effect completely inhibited by a neutralizing anti-H-ferritin antibody. The apoptosis induction appears to be related to a 43 kDa ferritin subunit contained in the isoferritins released from primary hepatocytes, presumably representing a ferritin heavy/light chain heterodimer. In addition, these isoferritins immunologically crossreact with antibodies raised against placental isoferritin p43-PLF (which also contains a 43 kDa ferritin subunit) and melanoma-derived H-chain ferritin, representing ferritin isoforms which reveal immunomodulatory properties. Furthermore, p53 and FasL are upregulated upon isoferritin treatment in a time dependent mode, and apoptosis induction can be suppressed by neutralizing anti-FasL antibodies. Proapoptotic Bid is upregulated too and translocated into mitochondria in primary hepatocytes exposed to the isoferritins purified from the CM. Finally, epidermal growth factor (EGF) and dexamethasone (DEX), which counteract proapoptotic mitochondrial signalling, almost completely abolished the proapoptotic effect of the hepatocyte derived isoferritins. In conclusion, our findings demonstrate that acidic isoferritins with homology to immunomodulatory ferritin isoforms (p43-PLF, melanoma-derived-H-chain ferritin) are released from hepatocytes in vitro, and are able to stimulate upregulation of p53 and mediate apoptosis involving Fas (CD95) signalling as well as addressing the intrinsic mitochondrial proapoptotic pathway.