Assessing the utility of DNA barcoding in wildlife forensic cases involving South African antelope

• Main Authors: Desiré Lee Dalton, Marli de Bruyn, Tia Thompson, Antoinette Kotzé
• Format: Article
• Language: English
• Published: Elsevier 2020-12-01
• Series: Forensic Science International: Reports
• Subjects: Forensics; Wildlife; Antelope; DNA barcoding
• Online Access: http://www.sciencedirect.com/science/article/pii/S2665910720300177

Poaching of South African wildlife is considered a threat to biodiversity. In the absence of diagnostic morphometric traits, DNA barcoding is considered as a method of choice for species identification. Here, we report on forensic case work involving the illegal hunting of antelope species. Three forensic cases which included confiscated material were submitted between 2018 and 2019 and for species identification. Laboratory procedures including DNA extraction and sequencing of cytochrome c oxidase 1 (COI) and cytochrome b (cytb) were conducted following forensic procedures to determine species identification. Generated sequences matched to reference sequences on the National Centre for Biotechnology Information (NCBI) and the Barcode of Life Data Systems (BOLD) to impala (Aepyceros melampus, 99.4–99.7 % homology), eland (Tragelaphus oryx, 99.8–100 % homology) and kudu (T. strepsiceros, 99.6–99.7 % homology). Phylogenetic analysis and intra- and interspecies distance further confirmed species identification with high bootstrap support (96–100 %). Average intraspecies sequence divergence was 0–1.15% and pairwise comparisons between taxa satisfied the 10-fold genetic distance. Thus both COI and cytb barcoding genes are suitable methodologies for forensic identification of species in the cases presented here. However, analysis of the reference samples identified species where barcoding may potentially fail. These include taxa that have undergone recent, rapid radiations resulting in high intraspecies distance or species that can hybridize. We thus recommend in these cases a reference database that includes geographically widespread samples is required and analysis with additional mitochondrial and/or nuclear markers.