Comparative evaluation of the MAPlex, Precision ID Ancestry Panel, and VISAGE Basic Tool for biogeographical ancestry inference.

Biogeographical ancestry (BGA) inference from ancestry-informative markers (AIMs) has strong potential to support forensic investigations. Over the past two decades, several forensic panels composed of AIMs have been developed to predict ancestry at a continental scale. These panels typically comprise fewer than 200 AIMs and have been designed and tested with a limited set of populations. How well these panels recover patterns of genetic diversity relative to larger sets of markers, and how accurately they infer ancestry of individuals and populations not included in their design remains poorly understood. The lack of comparative studies addressing these aspects makes the selection of appropriate panels for forensic laboratories difficult. In this study, the model-based genetic clustering tool STRUCTURE was used to compare three popular forensic BGA panels: MAPlex, Precision ID Ancestry Panel (PIDAP), and VISAGE Basic Tool (VISAGE BT) relative to a genome-wide reference set of 10k SNPs. The genotypes for all these markers were obtained for a comprehensive set of 3957 individuals from 228 worldwide human populations. Our results indicate that at the broad continental scale (K=6) typically examined in forensic studies, all forensic panels produced similar genetic structure patterns compared to the reference set (G'≈90%) and had high classification performance across all regions (average AUC-PR > 97%). However, at K= 7 and K= 8, the forensic panels displayed some region-specific clustering deviations from the reference set, particularly in Europe and the region of East and South-East Asia, which may be attributed to differences in the design of the respective panels. Overall, the panel with the most consistent performance in all regions was VISAGE BT with an average weighted AUC̅W score of 96.26% across the three scales of geographical resolution investigated.

Phylogeography and population genetic structure of the European roe deer in Switzerland following recent recolonization.

In the early 1800s, the European roe deer (Capreolus capreolus) was probably extirpated from Switzerland, due to overhunting and deforestation. After a federal law was enacted in 1875 to protect lactating females and young, and limiting the hunting season, the roe deer successfully recovered and recolonized Switzerland. In this study, we use mitochondrial DNA and nuclear DNA markers to investigate the recolonization and assess contemporary genetic structure in relation to broad topographic features, in order to understand underlying ecological processes, inform future roe deer management strategies, and explore the opportunity for development of forensic traceability tools. The results concerning the recolonization origin support natural, multidirectional immigration from neighboring countries. We further demonstrate that there is evidence of weak genetic differentiation within Switzerland among topographic regions. Finally, we conclude that the genetic data support the recognition of a single roe deer management unit within Switzerland, within which there is a potential for broad-scale geographic origin assignment using nuclear markers to support law enforcement.

Coral-ID: A forensically validated genetic test to identify precious coral material and its application to objects seized from illegal traffic.

The production and trade of objects manufactured from the skeletal axis of coralid precious corals is a historically, culturally and economically important global industry. Coralids are members of the diverse Coralliidae family, which contains several species complexes and morphospecies. For most precious coral found in the jewelry trade, the color remains the sole clue and link to the taxonomic identity of the individual. Different coralid species have however similar or overlapping colors resulting in difficulty to taxonomically identify jewelry objects, including four species listed by the Convention on the International Trade of Endangered Species (CITES) whose international transport and trade requires species-specific and country of origin documentation. We aimed at developing a reliable method to taxonomically identify coralid material with the objective of distinguishing CITES protected species from their non-protected counterparts. We present Coral-ID, a genetic assay to taxonomically classify coralid objects using quasi non-destructive sampling. The assay classifies the analyzed sample in one of six taxonomic categories and performs at least presumptive separation of CITES-listed and non-listed species in all cases. Developmental validation experiments prove that Coral-ID is a specific, accurate and very sensitive method. As the first attempt to randomly sample corals in the trade to identify them, we applied Coral-ID on 20 precious coral objects seized by custom authorities upon import to in Switzerland. Thirteen (65%) of these samples could be analyzed; three of these were found to be presumptively CITES-listed, and 10 of them have proven to originate from non-CITES-listed species.

19th century family saga re-told by DNA recovered from postcard stamps.

Old postcards with stamps might help unravelling historical family stories and relationships. By employing ancient DNA recovered from world war I postage stamps, we disprove a family saga of an illegitimate child born in 1887. We developed a protocol to collect DNA from saliva, trapped and protected on the backside of postage stamps glued on postcards. With replicate STR analyses we were able to assemble almost full autosomal and Y-STR profiles of three male, deceased family members. The illegitimate child turned out to be a legitimate child of a later married couple.

Sampling touch DNA from human skin following skin-to-skin contact in mock assault scenarios-A comparison of nine collection methods.

Collection of touch DNA from an offender on the victim's skin can provide relevant evidence for investigations of criminal cases. Therefore, the choice of the optimal sample collection method is crucial. In this study, we investigated the recovery of STR profiles from touch DNA on human skin by comparing nine different collection methods: the dry and wet cotton swabs in three different movements, the double-swab (wet-dry) method, the wet and dry Copan FLOQSwabs™, and the Scene Safe FAST™ minitapes. Mock assault scenarios were conducted with a male offender grasping the forearms of a female victim. Samples were collected from the assaulted area of the victim's skin, and the recovery of the offender's STR profile was evaluated. Our results indicate that the different swabs and swabbing techniques did not have a distinct impact on the STR recovery; however, the lowest STR recovery was achieved with Scene Safe FAST™ minitapes. In addition, we compared the double-swab method to the single-swab method by analyzing the DNA quantity of the wet and dry swabs separately. We found on average 13.7% more offender DNA using the double-swab method, but this did not translate into higher STR recovery. Our findings indicate that several methods perform equally well when collecting touch DNA from human skin, although SceneSafe FAST™ minitapes seem to be the least adequate for this purpose.

Developmental validation of Oxford Nanopore Technology MinION sequence data and the NGSpeciesID bioinformatic pipeline for forensic genetic species identification.

Species identification of non-human biological evidence through DNA nucleotide sequencing is routinely used for forensic genetic analysis to support law enforcement. The gold standard for forensic genetics is conventional Sanger sequencing; however, this is gradually being replaced by high-throughput sequencing (HTS) approaches which can generate millions of individual reads in a single experiment. HTS sequencing, which now dominates molecular biology research, has already been demonstrated for use in a number of forensic genetic analysis applications, including species identification. However, the generation of HTS data to date requires expensive equipment and is cost-effective only when large numbers of samples are analysed simultaneously. The Oxford Nanopore Technologies (ONT) MinION™ is an affordable and small footprint DNA sequencing device with the potential to quickly deliver reliable and cost effective data. However, there has been no formal validation of forensic species identification using high-throughput (deep read) sequence data from the MinION making it currently impractical for many wildlife forensic end-users. Here, we present a MinION deep read sequence data validation study for species identification. First, we tested whether the clustering-based bioinformatics pipeline NGSpeciesID can be used to generate an accurate consensus sequence for species identification. Second, we systematically evaluated the read variation distribution around the generated consensus sequences to understand what confidence we have in the accuracy of the resulting consensus sequence and to determine how to interpret individual sample results. Finally, we investigated the impact of differences between the MinION consensus and Sanger control sequences on correct species identification to understand the ability and accuracy of the MinION consensus sequence to differentiate the true species from the next most similar species. This validation study establishes that ONT MinION sequence data used in conjunction with the NGSpeciesID pipeline can produce consensus DNA sequences of sufficient accuracy for forensic genetic species identification.

DNA fingerprinting: an effective tool for taxonomic identification of precious corals in jewelry.

Precious coral species have been used to produce jewelry and ornaments since antiquity. Due to the high value and demand for corals, some coral beds have been heavily fished over past centuries. Fishing and international trade regulations were put in place to regulate fishing practices in recent decades. To this date, the control of precious coral exploitation and enforcement of trade rules have been somewhat impaired by the fact that different species of worked coral samples can be extremely difficult to distinguish, even for trained experts. Here, we developed methods to use DNA recovered from precious coral samples worked for jewelry to identify their species. We evaluated purity and quantity of DNA extracted using five different techniques. Then, a minimally invasive sampling protocol was tested, which allowed genetic analysis without compromising the value of the worked coral objects.The best performing DNA extraction technique applies decalcification of the skeletal material with EDTA in the presence of laurylsarcosyl and proteinase, and purification of the DNA with a commercial silica membrane. This method yielded pure DNA in all cases using 100 mg coral material and in over half of the cases when using "quasi non-destructive" sampling with sampled material amounts as low as 2.3 mg. Sequence data of the recovered DNA gave an indication that the range of precious coral species present in the trade is broader than previously anticipated.

Persistence and detection of touch DNA and blood stain DNA on pig skin exposed to water.

As it is unclear if and how long DNA evidence can persist on submerged skin, we examined the potential for recovery of touch DNA and blood stain DNA from skin samples immersed in different aquatic environments and temperatures for forensic purposes in this proof-of-concept study. We used pig skin, either smeared with human blood or held firmly for 30 s by two test-persons, before immersing it in either cold, room-temperature or warm water as well as in a stream and a pond for up to seven days prior to DNA testing. The samples were then typed at 16 STR loci. Cold water samples yielded the most promising results, as shown by the recovery of the full set of 16 reproducible STR loci from the touch DNA sample of one test-person after 7 days. For blood stains, we were able to recover all 16 reproducible STRs after 2 days. Room-temperature water and warm water yielded varying results for both blood stain DNA and touch DNA. For pond and stream samples, DNA recovery was possible only within two days. While the pond and stream samples were at relatively cold temperatures, DNA recovery may have been affected by the presence of water insects and snails in the pond and mud in the stream. Our findings show the potential of using immersed samples, particularly those immersed in cold water, as we could detect a complete DNA profile from blood stains and from touch DNA after several days. Our study opens the way for future in-depth studies, examining larger datasets and a wider range of conditions.

Microbiome-based body fluid identification of samples exposed to indoor conditions.

In the forensic reconstruction of crime scene activities, the identification of biological traces and their bodily origin are valuable evidence that can be presented in court. While several presumptive and confirmatory tests are currently available, the limitations in specificity and sensitivity have instigated a search for alternative methods. Bacterial markers have been proposed as a novel approach for forensic body fluid/tissue identification. Bacteria are not only ubiquitous throughout the human body, but also, as shown by recent microbiome sequencing studies of the 16S rRNA gene, bacterial community structures are distinct across body sites. Traces and stains at crime scenes are, however, often exposed to the environment outside the human body for variable periods of time before laboratory processing. Thus, it is not clear whether exposed samples continue to harbor microbial signatures characteristic of their body site of origin. In this proof-of-concept study we collected samples from six different body sites: saliva, skin, peripheral blood, vaginal fluid, menstrual blood and semen. We exposed a subset of these samples to indoor conditions for 30 days while the remaining samples were processed directly after extraction. Our analyses of 16S rRNA gene sequence data for a total of 46 control and exposed samples show that both types of samples group by body site, although a few outliers are observed. Based on our results, vaginal and menstrual samples share their microbial signatures, and cannot be distinguished using bacterial markers. Overall, our findings indicate that bacterial markers are a promising avenue for forensic body fluid/tissue identification.

[Tracking down the culprit - mRNA profiling for the identification of body fluids]. / Dem Täter auf der Spur - Nachweis von Körpersekreten mittels mRNA-Profiling.

Elderly patients may be different from the average population in regard to the treatment of shoulder disorders. Challenges are the decreased quality of bone, tendons and cartilage, decreased blood perfusion and a generally aged biology. The advantages however are the often more realistic expectations and more cautious use of the extremity, and the limited life expectancy of prosthetic implants is a less pressing issue. Local pathologies such as in the AC-joint or long head of the biceps may also in the aged patient be treated with infiltration or arthroscopic means. If however large rotator cuff tears and osteoarthritis are present, (reverse) total shoulder implants are the treatment of choice due to the high reliability and uncomplicated rehabilitation.

Allelic proportions of 16 STR loci-including the new European Standard Set (ESS) loci-in a Swiss population sample.

Allele frequencies and forensically relevant population statistics of 16 STR loci, including the new European Standard Set (ESS) loci, were estimated from 668 unrelated individuals of Caucasian appearance living in different parts of Switzerland. The samples were amplified with a combination of the following three kits: AmpFlSTR® NGM SElect™, PowerPlex® ESI17 and PowerPlex® ESX 17. All loci were highly polymorphic and no significant departure from Hardy-Weinberg equilibrium and linkage equilibrium was detected after correction for sampling.

Germline mutations of STR-alleles include multi-step mutations as defined by sequencing of repeat and flanking regions.

Well defined estimates of mutation rates are a prerequisite for the use of short tandem repeat (STR-) loci in relationship testing. We investigated 65 isolated genetic inconsistencies, which were observed within 50,796 allelic transfers at 23 STR-loci (ACTBP2 (SE33), CD4, CSF1PO, F13A1, F13B, FES, FGA, vWA, TH01, TPOX, D2S1338, D3S1358, D5S818, D7S820, D8S1132, D8S1179, D12S391, D13S317, D16S539, D17S976, D18S51, D19S433, D21S11) in Caucasoid families residing in Austria and Switzerland. Sequencing data of repeat and flanking regions and the median of all theoretically possible mutational steps showed valuable information to characterise the mutational events with regard to parental origin, change of repeat number (mutational step size) and direction of mutation (losses and gains of repeats). Apart from predominant single-step mutations including one case with a double genetic inconsistency, two double-step and two apparent four-step mutations could be identified. More losses than gains of repeats and more mutations originating from the paternal than the maternal lineage were observed (31 losses, 22 gains, 12 losses or gains and 47 paternal, 11 maternal mutations and 7 unclear of parental origin). The mutation in the paternal germline was 3.3 times higher than in the maternal germline. The results of our study show, that apart from the vast majority of single-step mutations rare multi-step mutations can be observed. Therefore, the interpretation of mutational events should not rigidly be restricted to the shortest possible mutational step, because rare but true multi-step mutations can easily be overlooked, if haplotype analysis is not possible.

Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins.

We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment. They both have suffered from generalized seizures since their early adulthood. Moreover, the patients showed some additional conditions only occurring in one individual or the other such as migraine, marked recurrent depressive disorder or polyarthrosis. The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients.