A Genomic Method for Combating Wildlife Trafficking: SNP-Based Traceability of Four Endangered Species in China

Wildlife trafficking poses a severe threat to global biodiversity and ecosystem stability, necessitating robust forensic tools for tracing the origins of illegally traded taxa. In this study, we developed a method of single-nucleotide polymorphism (SNP)-based molecular markers to enable precise geographical traceability of four animal species native to China: the Tibetan macaque (Macaca thibetana), brown eared pheasant (Crossoptilon mantchuricum), blue eared pheasant (Crossoptilon auritum), and Chinese pangolin (Manis pentadactyla). We studied these four species because their DNA is characterized by distinct population genetic structure, they are subjected to illegal trafficking, and given their diverse evolutionary histories, this allowed us to assess the general applicability of our forensic genetic framework in reducing wildlife crime. Based on whole-genome resequencing data from 26 Tibetan macaques, 51 eared pheasants and 42 Chinese pangolins, we performed population genetic analyses to elucidate their genetic structure and identify population-specific loci. The results indicated that all samples from these four species showed clear genetic differentiation and distinct clustering, allowing us to design primers to facilitate PCR-based traceability. We also assessed the utility of mitochondrial DNA (mtDNA) for tracing Tibetan macaques and both species of eared pheasants. We found that traceability accuracy using mtDNA was lower than when using SNPs. Our research offers a SNP-based traceability framework that accurately determines the geographical origin of wildlife samples to the genetic population level, and this provides a powerful tool for combating illegal trade and aiding conservation efforts.