Species identification in forensic samples using the SPInDel approach: A GHEP-ISFG inter-laboratory collaborative exercise

Using plants in forensics: State-of-the-art and prospects

The increasing use of plant evidence in forensic investigations gave rise to a powerful new discipline - Forensic Botany - that analyses micro- or macroscopic plant materials, such as the totality or fragments of an organ (i.e., leaves, stems, seeds, fruits, roots) and tissue (i.e., pollen grains, spores, fibers, cork) or its chemical composition (i. e., secondary metabolites, isotopes, DNA, starch grains). Forensic botanists frequently use microscopy, chemical analysis, and botanical expertise to identify and interpret evidence crucial to solving civil and criminal issues, collaborating in enforcing laws or regulations, and ensuring public health safeguards. The present work comprehensively examines the current state and future potential of Forensic Botany. The first section conveys the critical steps of plant evidence collection, documentation, and preservation, emphasizing the importance of these initial steps in maintaining the integrity of the items. It explores the different molecular analyses, covering the identification of plant species and varieties or cultivars, and discusses the limitations and challenges of these techniques in forensics. The subsequent section covers the diversity of Forensic Botany approaches, examining how plant evidence exposes food and pharmaceutical frauds, uncovers insufficient or erroneous labeling, traces illegal drug trafficking routes, and combats the illegal collection or trade of protected species and derivatives. National and global security issues, including the implications of biological warfare, bioterrorism, and biocrime are addressed, and a review of the contributions of plant evidence in crime scene investigations is provided, synthesizing a comprehensive overview of the diverse facets of Forensic Botany.

African or Asiatic origin? Genome analyses solved the mystery of the hybrid origin of the rescued lion cub

Species assignment of any seized material using DNA analysis has been a routine and widely accepted standard procedure in providing scientific advisory for the legal prosecution of wildlife cases. Scientific advancements and rigorous application of genetic tools have led to the development of a variety of molecular markers with their defined efficacy in wildlife forensics. However, in a few unusual cases where a hybrid needs to be identified or assignment need to be made at sub-species level, mitochondrial markers often fail or else provide biased results, which can affect the overall judgment in the court of law. Here, we report one such challenging case of lion cub rescued by the law enforcement from illegal trafficking. Phylogenetic assessment based on complete mitogenome assigned rescued lion cub with African lion (Panthera leo leo). However, the TSPY gene of the Y chromosome established that the lion cub shared its paternal lineage from Asiatic lion (Panthera leo persica). With the use of maternally and paternally inherited markers, we conclude a hybrid origin of the rescued lion cub which shared ancestry from both Asiatic as well as African lion. The present study exhibits the application of genome sequencing in thinking beyond routine identification and contributes to the operating procedures of wildlife forensics.

International Wildlife Trafficking: A perspective on the challenges and potential forensic genetics solutions

International wildlife trafficking (IWT) is a thriving and pervasive illegal enterprise that adversely affects modern societies. Yet, despite being globally recognized as a threat to biodiversity, national security, economy, and biosecurity, IWT remains largely unabated and is proliferating at an alarming rate. The increase in IWT is generally attributed to a lack of prioritization to curb wildlife crime through legal and scientific infrastructure. This review: (1) lays out the damaging scope and influence of IWT; (2) discusses the potential of DNA marker systems, barcodes, and emerging molecular technologies, such as long-read portable sequencing, to facilitate rapid, in situ identification of species and individuals; and (3) encourages initiatives that promote quality and innovation. Interdisciplinary collaboration promises to be one of the most effective ways forward to surmounting the complex scientific and legal challenges posed by IWT.

Development and Validation of a Novel Five-Dye Short Tandem Repeat Panel for Forensic Identification of 11 Species

Species identification of unknown biological samples is of fundamental importance for forensic applications, especially in crime detection, poaching, and illegal trade of endangered animals as well as meat fraud. In this study, a novel panel was developed to simultaneously identify 10 different animal species (Gallus domesticus, Anas platyrhynchos domesticus, Ovis aries, Sus scrofa domesticus, Bos taurus, Equus caballus, Columba livia domestica, Rattus norvegicus, Mus musculus, and Canis lupus familiaris) and human beings by amplifying 22 short tandem repeat (STR) loci in a multiplex PCR using a set of five fluorescently labeled dyes. This novel 22-STR panel was validated by optimization of PCR conditions as well as species specificity, sensitivity, reproducibility, precision, DNA mixture, and tissue/organ consistency. The results of developmental validation showed that the 22-STR loci achieved high species specificity among 10 animal species and human beings, and the sensitivity of this panel was 0.09 ng. This 22-STR panel identified different meats in mixed samples, and the minimum detected mixture ratio in the current test was 10% (0.1 ng/1 ng). This sensitive, accurate, and specific 22-STR panel can be used for forensic species identification and the detection of meat fraud and adulteration.

Wildlife forensics: A boon for species identification and conservation implications

Wildlife trade and fraudulence in food, artefacts and cosmetic industries had raised serious concern in protection of the wild faunal diversity. Lack of proper tools and molecular based techniques for identification of wild species are some of the major constrains faced by the judiciary and law enforcement agencies while framing charges against poachers and illicit agitator. The emergence of wildlife forensics serves as a boon in solving long pending cases of wildlife crimes. Wildlife forensics have proven to be fast, accurate and reliable criminal investigation processes with comprehensive coverage and easy accessibility. It has also helped resolving taxonomic disputes, determining spatiotemporal genetic divergence, evolutionary history, origins and even endemism. Collaboration among inter-disciplinary fields has even led to engineered signature markers and phylogenetics for several species. Development in fields of genetics, molecular and evolutionary biology and other omics techniques have further contributed in accurate identification of species. Wildlife forensics, with the support of proper international mega database units for population reference, will be fundamental in wildlife investigations through its unlimited information sharing ability. The efficient conservation of species will, however, require a collaborative approach consisting of national policy makers, local stakeholders and implementation agencies in addition to experts from the scientific communities.

Species assignment in forensics and the challenge of hybrids

Forensic identification of species is in growing demand, particularly from law enforcement authorities in the areas of wildlife, fisheries and hunting as well as food authentication. Within the non-human forensic genetics expanding applications' field, the major current difficulties result from the lack of standards and genetic databases as well as the poor or absent taxonomic definition of several groups. Here we focus on a forensically important and overlooked problem in species identification: the exclusive use of uniparental markers, a common practice in current genetic barcoding methodologies, may lead to incorrect or impossible assignment whenever hybrids can occur (frequently, not only in domesticates, but also in the wild). For example, if one of these cases involves a mammal, and mitochondrial DNA alone is used (which in instances may be the only type of DNA sequence available in databases), the sample will be wrongfully assigned to the female parental species, completely missing the detection of a possible hybrid animal. The importance of this issue in the forensic contributions to food authentication, wildlife and conservation genetics is analyzed. We present a cautionary guidance on the forensic reporting of results avoiding this error.

Identification of plant species using variable length chloroplast DNA sequences

The correct identification of species in the highly divergent group of plants is crucial for several forensic investigations. Previous works had difficulties in the establishment of a rapid and robust method for the identification of plants. For instance, DNA barcoding requires the analysis of two or three different genomic regions to attain reasonable levels of discrimination. Therefore, new methods for the molecular identification of plants are clearly needed. Here we tested the utility of variable-length sequences in the chloroplast DNA (cpDNA) as a way to identify plant species. The SPInDel (Species Identification by Insertions/Deletions) approach targets hypervariable genomic regions that contain multiple insertions/deletions (indels) and length variability, which are found interspersed with highly conserved regions. The combination of fragment lengths defines a unique numeric profile for each species, allowing its identification. We analysed more than 44,000 sequences retrieved from public databases belonging to 206 different plant families. Four target regions were identified as suitable for the SPInDel concept: atpF-atpH, psbA-trnH, trnL CD and trnL GH. When considered alone, the discrimination power of each region was low, varying from 5.18% (trnL GH) to 42.54% (trnL CD). However, the discrimination power reached more than 90% when the length of some of these regions is combined. We also observed low diversity in intraspecific data sets for all target regions, suggesting they can be used for identification purposes. Our results demonstrate the utility of the SPInDel concept for the identification of plants.

An internationally standardized species identification test for use on suspected seized rhinoceros horn in the illegal wildlife trade

Rhinoceros (rhino) numbers have dwindled substantially over the past century. As a result, three of the five species are now considered to be critically endangered, one species is vulnerable and one species is near-threatened. Poaching has increased dramatically over the past decade due to a growing demand for rhino horn products, primarily in Asia. Improved wildlife forensic techniques, such as validated tests for species identification of seized horns, are critical to aid current enforcement and prosecution efforts and provide a deterrent to future rhino horn trafficking. Here, we present an internationally standardized species identification test based on a 230 base pair cytochrome-b region. This test improves on previous nested PCR protocols and can be used for the discrimination of samples with <20pg of template DNA, thus suitable for DNA extracted from horn products. The assay was designed to amplify water buffalo samples, a common 'rhino horn' substitute, but to exclude human DNA, a common contaminant. Phylogenetic analyses using this partial cytochrome-b region resolved the five extant rhino species. Testing successfully returned a sequence and correct identification for all of the known rhino horn samples and vouchered rhino samples from museum and zoo collections, and provided species level identification for 47 out of 52 unknown samples from seizures. Validation and standardization was carried out across five different laboratories, in four different countries, demonstrating it to be an effective and reproducible test, robust to inter laboratory variation in equipment and consumables (such as PCR reagents). This is one of the first species identification tests to be internationally standardized to produce data for evidential proceedings and the first published validated test for rhinos, one of the flagship species groups of the illegal wildlife trade and for which forensic tools are urgently required. This study serves as a model for how species identification tests should be standardized and disseminated for wildlife forensic testing.