Development of a multiplex, PCR-based genotyping assay for African and Asian elephants for forensic purposes

African and Asian elephant ivory discrimination using a portable strip test

Currently, the global elephant population has significantly declined due to the poaching of elephants for their ivory, and this is the reason why elephants are listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). However, Thailand allows the legal trade of ivory from registered, domesticated Asian elephants, leading to the smuggling of African elephant ivory, and passing them off as Asian elephant ivory. Therefore, this research aims to develop and validate a portable strip test to discriminate between Asian and African elephants DNA, using Recombinase Polymerase Amplification (RPA) and Lateral Flow Dipstick assay (LFD) according to international standards. The results showed that the strip test can be successfully developed with 100% accuracy (n = 105). This kit is specific to elephants, has a detection limit of 0.125 ng of DNA, and can effectively discriminate a variety of elephant ivory, including raw ivory, ivory products, and aged ivory over 25 years old, which had been damaged by fire, all with 100% accuracy (n = 117). Additionally, the developed strip test is designed to be portable and cost-effective. It does not require expensive laboratory equipment and provides a faster analysis process compared with conventional PCR-based methods. This will expedite the legal process and enforcement of laws related to elephant conservation, reducing the opportunities for illegal activities, and enabling timely prosecution under relevant wildlife conservation laws in Thailand and internationally.

Capillary-Electrophoresis-Based Species Barcoding of Big Cats: CR-mtDNA-Length Polymorphism

This study aimed to provide an overview of the methodological approach used for the species determination of big cats. The molecular system described herein employs mitochondrial DNA control region (CR-mtDNA)-length polymorphism in combination with highly sensitive and precise capillary electrophoresis. We demonstrated that the described CR-mtDNA barcoding system can be utilized for species determination where the presence of biological material from big cats is expected or used as a confirmatory test alongside Sanger or massive parallel sequencing (MPS). We have also addressed the fact that species barcoding, when based on the analysis of mtDNA targets, can be biased by nuclear inserts of the mitochondrial genome (NUMTs). The CR-mtDNA barcoding system is suitable even for problematic and challenging samples, such as hair. CR-mtDNA-length polymorphisms can also distinguish hybrids from pure breeds.

A new multiplex qPCR assay to detect and differentiate big cat species in the illegal wildlife trade

All species of big cats, including tigers, cheetahs, leopards, lions, snow leopards, and jaguars, are protected under the Convention on the International Trade in Endangered Species (CITES). This is due in large part to population declines resulting from anthropogenic factors, especially poaching and the unregulated and illegal trade in pelts, bones, teeth and other products that are derived from these iconic species. To enhance and scale up monitoring for big cat products in this trade, we created a rapid multiplex qPCR test that can identify and differentiate DNA from tiger (Panthera tigris), cheetah (Acinonyx jubatus), leopard (Panthera pardus), lion (Panthera leo), snow leopard (Panthera uncia), and jaguar (Panthera onca) in wildlife products using melt curve analysis to identify each species by its unique melt peak temperature. Our results showed high PCR efficiency (> 90%), sensitivity (detection limit of 5 copies of DNA per PCR reaction) and specificity (no cross amplification between each of the 6 big cat species). When paired with a rapid (< 1 h) DNA extraction protocol that amplifies DNA from bone, teeth, and preserved skin, total test time is less than three hours. This test can be used as a screening method to improve our understanding of the scale and scope of the illegal trade in big cats and aid in the enforcement of international regulations that govern the trade in wildlife and wildlife products, both ultimately benefiting the conservation of these species worldwide.

The Revolution of Animal Genomics in Forensic Sciences

Nowadays, the coexistence between humans and domestic animals (especially dogs and cats) has become a common scenario of daily life. Consequently, during a forensic investigation in civil or criminal cases, the biological material from a domestic animal could be considered "evidence" by law enforcement agencies. Animal genomics offers an important contribution in attacks and episodes of property destruction or in a crime scene where the non-human biological material is linked to the victim or perpetrator. However, only a few animal genetics laboratories in the world are able to carry out a valid forensic analysis, adhering to standards and guidelines that ensure the admissibility of data before a court of law. Today, forensic sciences focus on animal genetics considering all domestic species through the analysis of STRs (short tandem repeats) and autosomal and mitochondrial DNA SNPs (single nucleotide polymorphisms). However, the application of these molecular markers to wildlife seems to have gradually gained a strong relevance, aiming to tackle illegal traffic, avoid the loss of biodiversity, and protect endangered species. The development of third-generation sequencing technologies has glimmered new possibilities by bringing "the laboratory into the field", with a reduction of both the enormous cost management of samples and the degradation of the biological material.

Cross-Amplification in Strigiformes: A New STR Panel for Forensic Purposes

Strigiformes are affected by a substantial decline mainly caused by habitat loss and destruction, poaching, and trapping. Moreover, the increasing trend in bird trade and the growing interest in wild-caught rather than captive-bred birds are expected to encourage illegal trade. The biomolecular investigation represents a valuable tool to track illegal trade and to explore the genetic variability to preserving biodiversity. Microsatellite loci (STRs) are the most used markers to study genetic variability. Despite the availability of species-specific microsatellite loci in Strigiformes, a unique panel permitting the description of the genetic variability across species has not been identified yet. We tested 32 highly polymorphic microsatellite markers to evaluate the reliability of a unique microsatellite panel in different species of Strigiformes and its use for conservation and forensic purposes. We included in the study 84 individuals belonging to 28 parental groups and 11 species of Strigiformes. After screening polymorphic microsatellite loci, the description of genetic variability, and the kinship assessment, we characterized a final panel of 12 microsatellite loci able to identify individuals in 9 Strigiformes species. This STR panel might support the authorities in the forensic investigation for suspected smugglers and false parental claims; moreover, it can be useful to evaluate relatedness among individuals in captive-bred populations and to implement research projects finalized to the description of the genetic variability in wild populations.