Search Results (241)

Background/Objectives: Interpretation of mixture profiles generated from crime scene samples is an important element in forensic genetics. Here, a workflow for mixture deconvolution of sequenced microhaplotypes (MHs) and STRs using the probabilistic genotyping software MPSproto v0.9.7 was developed, and the performance of the two types of loci was compared. Methods: Sequencing data from a custom panel of 74 MHs (the MH-74 plex) and a commercial kit with 26 autosomal STRs (the ForenSeq™ DNA Signature Prep Kit) were used. Single-source profiles were computationally combined to create 360 two-person and 336 three-person mixtures using the Python script MixtureSimulator v1.0. Additionally, 72 real mixtures typed with the MH-74 plex and 18 real mixtures typed with the ForenSeq Kit from a previous study were deconvoluted using MPSproto. Results: The deconvoluted MH profiles were more complete and had fewer wrong genotype calls than the deconvoluted STR profiles. The contributor proportion estimates were more accurate for MH profiles than for STR profiles. Wrong genotype calls were mostly caused by locus and heterozygous imbalances, noise reads, or an inaccurate contributor proportion estimation. The latter was especially problematic in STR sequencing data, when two contributors contributed equally to the mixture. A total of 34,800 deconvolutions of the simulated mixtures were performed with two defined hypotheses: H_p, “The sample consists of DNA from one/two unknown contributor(s) and the suspect” and H_d, “The sample consists of DNA from two/three unknown individuals”. All true contributors were identified (LR > 10¹⁵ for MHs and LR > 10⁹ for STRs) and all non-contributors excluded (LR < 10⁻⁶ for MHs and LR < 0.2 for STRs). Conclusions: In simulated and real mixtures, the MHs performed better than STRs. Full article

Background/Objectives: Obtaining reliable DNA profiles from archival tissue preserved as formalin-fixed, paraffin-embedded (FFPE) samples remains a major challenge in both forensic and medical evaluations. The quality of DNA isolated from FFPE material is frequently compromised due to formalin-induced fragmentation and chemical modifications. These limitations are particularly relevant in cases of suspected medical malpractice related to cancer diagnosis or treatment, where retrospective molecular analyses may provide critical evidence. The aim of this study was to evaluate the performance of the Maxwell^® RSC Xcelerate DNA FFPE Kit (Promega) in generating DNA profiles from archival FFPE tissue blocks of endometrial cancer and to identify the limitations associated with this approach. Methods: Archival FFPE blocks of endometrial cancer were analyzed using the Maxwell^® RSC Xcelerate DNA FFPE Kit. DNA yield, purity, and degradation indices were assessed using standard real-time PCR-based quantification methods. Short tandem repeat (STR) profiling was performed with forensic genotyping kits, and the completeness, allele balance, and reliability of obtained profiles were evaluated. The obtained results were compared with reference quality thresholds commonly used in forensic practice. Results: The Maxwell^® RSC Xcelerate Kit allowed for recovery of relatively high DNA yields with consistently low degradation indices, confirming good extraction efficiency from FFPE samples. Nevertheless, despite favorable quantitative values, the generation of complete STR profiles was often unsuccessful. Partial or incomplete profiles were frequent, characterized by allele dropout and imbalance, which substantially reduced their evidentiary value. These findings suggest that DNA fragmentation and fixation-related artifacts impair amplification efficiency and limit the usefulness of STR analysis. Conclusions: This study emphasizes the persistent challenges of DNA profiling from FFPE tissue in forensic-medical contexts. Although the Maxwell^® RSC Xcelerate Kit demonstrated effective DNA recovery, the ability to generate complete and interpretable STR profiles remained limited. Further refinement of extraction protocols, as well as improved interpretative strategies, are required to enhance the reliability and evidentiary significance of molecular analyses based on archival FFPE material. Full article

Background/Objectives: Y-chromosomal short tandem repeats (Y-STR) are genetic markers widely used in forensic and population genetics. However, despite their importance, many populations remain under-represented in published studies and genetic databases. One such population is the Cape Verdean, which, despite its unique history of admixture between European and sub-Saharan African populations, continues to be under-represented in global Y-STR reference databases. This study aims to characterize the Y-STR haplotype diversity and paternal lineage composition of the Cape Verdean population using a high-resolution STR panel. Methods: A total of 143 unrelated Cape Verdean men were analyzed using a set of 26 Y-STR loci, including rapidly mutating markers. Allele and haplotype frequencies were calculated, along with standard forensic parameters such as gene and haplotype diversity. Paternal lineages were inferred, and genetic relationships with other populations were evaluated using distance-based and graphical methods. Results: A total of 135 haplotypes were detected, with 88.8% being unique, yielding a haplotype diversity of 0.999. The most common haplogroups reflected both West African and European ancestry. Genetic distance analysis positioned the Cape Verdean population between African and European groups, supporting its intermediate and admixed genetic background. Conclusions: This study provides the first high-resolution Y-STR dataset for Cape Verdeans, contributing valuable reference data for forensic casework and population genetic studies. The results highlight the utility of extended Y-STR panels in admixed populations and underscore the need to enhance the representation of admixed populations in international forensic reference databases. Full article

Myriophyllum heterophyllum is an aquatic macrophyte that is invasive to the northeastern United States and several western European countries. Spreading by vegetative clonal propagation, especially fragmentation, extensive resources are devoted to limiting its growth and spread; however, genetic assessments are not typically included in management strategies. Reduction in genetic (clonal) diversity should accompany biomass reduction, yet without genetic assessment, the efficacy of plant removal remains unclear. This paper is the first to describe a microsatellite marker library and its use in the characterization of Myriophyllum heterophyllum. Eighty-seven tissue samples were collected across the invasive distribution of Myriophyllum heterophyllum in Maine, USA. DNA was extracted, and PCR amplification was employed to screen 13 published microsatellites. Sequencing of the amplified loci was performed to characterize repeat motifs and confirm primer binding sites. Fragment sizing of PCR amplicons was employed to determine microsatellite lengths across the 87 samples. A total of 7 of the 13 tested markers were amplified, with six of those seven found to be variable. Polyploidy was evident from allelic diversity within individuals, although precise ploidy could not be determined. Observed heterozygosity ranged from 0.16 to 1.00 across variable markers. This seven-marker library was effective in characterizing the genetic diversity of both newly discovered (<5 years) and older (>50 years) infestations and is expected to be suitable for assessment of genetic diversity in populations within the native range of M. heterophyllum. The marker library also shows potential for use in several other Myriophyllum species. Full article

Background and Clinical Significance: Ovarian ectopic pregnancy (OEP) is a rare occurrence, and molar degeneration is even more exceptional. Differential diagnosis between a partial and complete hydatidiform mole is paramount as the complete type carries a higher risk of post-molar gestational trophoblastic neoplasia. Herein, we describe a case of a partial mole in an OEP (OPHM) with thorough investigations. Case Presentation: A 39-year-old woman presented at 6 weeks of amenorrhea with abdominal pain and vaginal bleeding. Ultrasound showed no intrauterine pregnancy, but an ovarian cyst suspicious for OEP. The patient underwent surgical removal of the cyst. Histological diagnosis was suspicious for OPHM with only one abnormal villous. Immunohistochemistry for p57^kip2 and fluorescent in situ hybridization (FISH) were not conclusive. STR-based (Short Tandem Repeat) molecular technique demonstrated the chromosomal asset of 69,XXX, confirming the diagnosis of OPHM. The patient was fully monitored for 1 year with periodic measurements of beta-hCG levels. After that period, the patient was in good health and disease-free. Conclusions: Histologically, ancillary techniques might not be sufficient to confirm the diagnosis of a hydatidiform mole, especially if the tissue available is scarce. In this case, STR has been demonstrated an effective tool in defining the chromosomal asset, even in paraffin-embedded samples. Full article

The immortal murine hepatic stellate cell line Col-GFP HSC was comprehensively characterized using genetic and molecular approaches. Short tandem repeat (STR) profiling and karyotyping combined with multiplex fluorescence in situ hybridization (M-FISH) confirmed the identity of the cell line and revealed no contamination. Col-GFP HSCs showed a near tetraploid karyotype. Additionally, next-generation sequencing (NGS) data, quantitative reverse transcription PCR, and Western blot analyses demonstrated robust expression of genes and proteins associated with hepatic stellate cells, including those involved in extracellular matrix remodeling and fibrogenic pathways. Phalloidin staining revealed filamentous actin patterns characteristic of stellate cells, providing additional support for their cytoskeletal organization and functional status. These findings provide strong evidence that the Col-GFP HSC cell line originates from hepatic stellate cells and can serve as a reliable in vitro model to study stellate cell biology and related pathophysiological processes. Full article

Histone post-translational modifications (PTMs) have emerged as promising epigenetic biomarkers with increasing forensic relevance. Unlike conventional genetic markers such as short tandem repeats (STRs), histone modifications can offer additional layers of biological information, capturing individual-specific regulatory states and remaining detectable even in degraded forensic samples. This review highlights recent advances in understanding histone PTMs in forensic contexts, focusing on three key domains: analysis of degraded biological evidence, differentiation of monozygotic (MZ) twins, and postmortem interval (PMI) estimation. We summarize experimental findings from human cadavers, animal models, and typical forensic samples including bone, blood, and muscle, illustrating the stability and diagnostic potential of marks such as H3K4me3, H3K27me3, and γ-H2AX. Emerging technologies including CUT&Tag, MALDI imaging, and nanopore-based sequencing offer novel opportunities to profile histone modifications at high resolution and low input. Despite technical challenges, these findings support the feasibility of histone-based biomarkers as complementary tools for forensic identification and temporal analysis. Future work should prioritize methodological standardization, inter-laboratory validation, and integration into forensic workflows. However, the forensic applicability of these modifications remains largely unvalidated, and further studies are required to assess their reliability in casework contexts. Full article

This study investigates the genetic diversity and population structure of Castanopsis tribuloides, a vital tree species in Asian forest ecosystems. Understanding the genetic patterns of keystone forest species provides critical insights into forest resilience and ecosystem function and informs conservation strategies. We analyzed population samples collected from three distinct locations within Doi Suthep Mountain in northern Thailand using Short Tandem Repeat (STR) markers to assess both intra- and inter-population genetic relationships. DNA was extracted from leaf samples and analyzed using a panel of polymorphic microsatellite loci specifically optimized for Castanopsis species. Statistical analyses included the assessment of forensic parameters (number of alleles, observed and expected heterozygosity, gene diversity, polymorphic information content), population differentiation metrics (G_ST), inbreeding coefficients (F_IS), and gene flow estimates (N_m). We further examined population history through bottleneck analysis using three models (IAM, SMM, and TPM) and visualized genetic relationships through principal coordinate analysis and cluster analysis. Our results revealed significant patterns of genetic structuring across the sampled populations, with genetic distance metrics showing statistically significant differentiation between certain population pairs. The PCA and cluster analyses confirmed distinct population groupings that correspond to geographic distribution patterns. These findings provide the first comprehensive assessment of C. tribuloides population genetics in this region, establishing baseline data for monitoring genetic diversity and informing conservation strategies. This research contributes to our understanding of how landscape features and ecological factors shape genetic diversity patterns in essential forest tree species, with implications for managing forest genetic resources in the face of environmental change. Full article

Tripterygium wilfordii has extremely important pharmaceutical value in both traditional and modern medicine. The mitogenome of T. wilfordii was subjected to assembly and annotation with Nanopore long reads and Illumina short reads in this study. The mitogenome is 720,306 bp in length and is responsible for encoding 55 specific genes, including 35 protein-coding genes (PCGs), 17 transfer RNA (tRNA) genes, and 3 ribosomal RNA (rRNA) genes. Upon repetitive sequence analysis, 223 simple sequence repeats (SSRs), 24 long tandem repeats (LTRs), and 47 dispersed repetitive sequences (DRSs) were identified. The 24 common PCGs were used for phylogenetic analysis, which revealed that T. wilfordii is more closely related to Euonymus alatus. Moreover, mitochondrial plastid DNA (MTPT) analysis revealed eight MTPTs in the mitochondrial genome. Furthermore, 600 RNA-editing sites were detected in the protein-coding genes according to RNA-seq results. Among these genes, the ccmB gene contained the greatest number of sites, followed by the nad4 gene. This is the first study to report the T. wilfordii mitogenome and illustrate its linear structure. The findings of this study will help elucidate the evolution of the T. wilfordii mitogenome and facilitate its potential application in genetic breeding. Full article

Background/Objectives: Standardbreds, a breed of horses used in harness racing at either the trot or the pace, established a closed studbook in 1973. Concerns about genetic diversity within the breed led the United States Trotting Association (USTA) to establish a limit of mares bred per stallion (i.e., a studbook cap) in 2009. Here, we aimed to evaluate the impact of the breeding restrictions on genetic diversity between and among subpopulations. Methods: Sixteen short tandem repeats (STRs) were analyzed across a dataset of 176,424 Standardbreds foaled in the United States between 1998 and 2021. We examined allelic richness (Na), number of effective alleles (Ne), expected heterozygosity (H_E), observed heterozygosity (H_O), inbreeding coefficient (F_IS), and fixation index (F_ST) across 24 years, differentiating by gate type, and comparing pre-(1998–2009) and post-(2010–2021) studbook cap periods using regression analysis. Results: Our results support decreased genetic diversity for both trotters and pacers over time. However, pacing Standardbreds exhibited significantly slower rates of decrease in genetic diversity after the 2009 studbook cap, as evidenced by Ne, H_E, and F_IS (P_Bonferroni < 0.01). Additionally, moderate levels of genetic differentiation were found between trotters and pacers (0.05 < F_ST < 0.09), which increased over time. Conclusions: Given that the rate of loss of diversity does not appear to differ pre and post studbook cap in trotters and that there is an increase in genetic differentiation between the groups over time, developing additional breeding tools and strategies is necessary to help the subpopulation mitigate further decline. Full article

This study aimed to determine the allele frequencies and genetic diversity of 21 autosomal short tandem repeat (STR) loci from the Expanded U.S. Core Loci and European Standard Set in the Romanian population. A random sample of 928 unrelated men from all Romanian counties was analyzed using the Investigator 24plex QS and Investigator 24plex GO! Kits (Qiagen). The genotypes were determined, and the allele frequencies were calculated using the STRidER tool. The results provide updated population genetic data for the Romanian population, which is essential for accurate calculation of DNA evidence weight in forensic casework. Full article

Yeast bloodstream infections lead to high mortality and morbidity and are mostly observed in immunocompromised patients. In Africa, only a few studies have characterized clinical yeasts. To increase insight into yeast resistance and transmission in Africa, we identified various yeasts from Alexandria, Egypt and performed antifungal susceptibility testing (AFST) and genotyping. A total of 1307 single isolates from unique patients, recovered from different anatomical sites including the bloodstream, retrieved from a reference laboratory in Alexandria, Egypt were studied. All isolates were identified with MALDI-TOF MS, while some were initially identified with a Vitek 2 Compact system. Short tandem repeat (STR) genotyping was performed for the most common species, and AFST was performed with microbroth dilution. Among bloodstream isolates (n = 71), C. albicans was the most common etiological agent, followed by C. tropicalis and C. parapsilosis. Comparison of yeast identification methods demonstrated that 22% of isolates were incorrectly identified with the Vitek 2 Compact system compared to MALDI-TOF MS. Multiple rare yeasts showed reduced antifungal susceptibility. STR genotyping demonstrated potential events of nosocomial transmission with N. glabratus and C. parapsilosis. Moreover, an azole-resistant C. tropicalis clade identified earlier in Alexandria was still present. To conclude, clinical yeasts in Alexandria, Egypt, are overall susceptible common species. Full article

Background: Studies on somatic mutations in cancer typically report single-nucleotide variants in coding regions, while mutations in short tandem repeats (STRs) are usually overlooked. Homopolymeric regions, a subset of STRs, are stretches of DNA where only a single nucleotide is repeated multiple times (e.g., AAAAA or TTTTT). Only recently have mutations in such STR regions been seen in colorectal cancer, where microsatellite instability (MSI) is common. In non-melanoma skin cancer (NMSC), MSI is rare. In this study, we focus on somatic mutations in such homopolymeric regions in NMSC and their functional implications. Methods: We performed targeted DNA sequencing (paired tissue and blood from the same individual), using more than 400 cancer-related genes from 32 NMSC patients as cases and non-lesional skin tissue from 16 independent individuals as controls. Results: We identified NMSC-associated STR somatic mutations. These are associated with the dysregulation of DNA damage and repair mechanisms. In artificial intelligence (AI) predictive modeling, these markers could successfully differentiate basal cell carcinoma (BCC) and non-lesional skin tissue. To our knowledge, we present the first study focusing on STR somatic mutations in multiple cancer-related genes in NMSC found only in tumor tissue and not in non-lesional skin tissue. Some of them (APC, BRAF) are associated with more pronounced dysregulation of relevant gene pathways (hedgehog, Notch signaling, and Wnt signaling). Conclusions: Our findings suggest that this STR somatic mutation status might potentially be used to select BCC patients who could benefit from certain precision therapy including hedgehog inhibitors, gamma-secretase inhibitors, anti-Vasuclar endothelial growth factor (VEGF), proteasome inhibitors, and immune check-point inhibitors. Full article

Objectives: To analyze Colombia’s current human population, we employed a population genetics approach enriched by genealogical, demographic, cultural, and historical data to learn about its evolutionary history and to elucidate ethnic belonging and relationship patterns between its various population groups. Materials and Methods: This study relied on ten autosomal microsatellite markers (STRs) from 1364 individuals surveyed throughout the country. Aside from employing descriptive population genetics, substructure, and distance analysis, this investigation evaluated genealogical, demographic, cultural, and historical data gathered from fieldwork surveys. Results: We present a genetic diversity and ethnic belonging map of Colombia that suggests a nine-population classification (under Afro-descendant, Native American, and Admixed ethnicity labels) that reveals traces of evolutionary processes discussed in the light of the recent literature based on modern molecular markers. Colombia’s genetic trace from Africa varies among territories, as shown here by two differentiated Afro ancestral components, Chocó and San Andrés, in addition to the Afro admixture category. Some Native American peoples like the Wayúu, Zenú, Ticuna, Huitoto, and Cocama have a genetic configuration that remains relatively preserved. Nevertheless, other self-determined indigenous peoples who remain in their ancestral territories exhibit genetic introgression that is also reflected by their acculturation levels such as the Pijaos, Kankuamos, and Mokaná. The population classified as European admixture also shows an ancestral component that seems to be more fixed throughout neighboring territories but whose fluctuation depends on its specific demographic histories. Conclusions: This study combines STRs, a targeted sampling strategy, and advanced analytical tools to explore Colombia’s genetic diversity and evolutionary history. Locally, these findings enhance the understanding of genetics in a post-conflict society, crucial for human identification. Globally, they contribute to human population genetics, helping address evolutionary questions using data from diverse human ancestries and geographies. Full article

A variable number tandem repeat polymorphism has been described in the CYP2C9 promoter (pVNTR) with three types of fragments: short (pVNTR-S), medium (pVNTR-M), and long (pVNTR-L). The pVNTR-S allele appears in strong linkage disequilibrium (LD) with the non-functional CYP2C9*3 allele in populations of European ancestry, but independently of this, it also appears to reduce the level of CYP2C9 expression in human liver by up to 34%. Objectives: This study, in a Dominican population with varying amounts of Western European, African, and Native American ancestry, aims primarily to determine the frequency of CYP2C9 pVNTR, and the degree of LD of pVNTR-S with CYP2C9*3. Secondarily, it explores if the frequency of the pVNTR-S allele is over- or under-represented in those with a greater component of African ancestry. Methods: A total of 193 healthy volunteers from the Dominican Republic participated in the study. The promoter region of CYP2C9 was amplified and analyzed by capillary electrophoresis. Analyses of CYP2C9 genotypes (*2, *3, *5, *6, and *8) and genetic ancestry, estimated in 176 Dominican individuals by genotyping 90 ancestry informative markers, were previously performed in this population. Results: The frequencies of CYP2C9 pVNTR-L, M, and S variants are 0.065, 0.896, and 0.039, respectively. LD between pVNTR-S and CYP2C9*3 was found (D’ = 0.756, r² = 0.702) to be weaker than in European populations. Conclusions: Populations with a greater African ancestry component appear to present a lower-than-expected frequency of pVNTR-S, as well as a lower tendency for this and CYP2C9*3 alleles to be inherited together, as is common in Europeans. The present exploratory results warrant further research in vivo about the effects of pVNTR-S in predicting CYP2C9 activity. Its inclusion in CYP2C9 testing panels for personalized drug therapy could be relevant in populations such as the Dominican, where the LD between pVNTR-S and CYP2C9*3 is low. Full article