Use of genetic evidence in the investigation of illegal reptile trafficking in Colombia. Case Report

Abstract

Introduction: In Colombia, the wildlife species trade without the necessary documentation is banned by law, so in the context of a criminal investigation into the sale of reptiles over the Internet, as part of a search procedure, the scene was processed. Objective: To make the most probable taxonomic assignment using genetic analysis in biological samples collected from the scene to establish the presence of reptiles, given the absence of animals at the time of the search. Methods: Six biological samples, including a skin shedding, surface swabbing and fecal samples were collected for their subsequent processing in the laboratory following the established analysis protocols.  DNA extraction was performed using a silica-based DNA isolation method and a 12S-120bp mitochondrial marker was amplified; the resulting fragments were sequenced and the sequences were compared with the information available in the Genbank database using the BLASTn algorithm. Results and discussion: Based on the data obtained from the comparison, 100% coverage and 100% identity, and after analyzing the characteristics of each taxonomic group and the available genetic information, the taxonomic assignment was made. In the skin shedding sample, difficulties were found for the amplification and sequencing of the entire fragment, which limited the use of larger markers, however, from the information obtained, the species identification for Boa constrictor (common boa) was achieved; In the case of feces samples and swabbing, the presence of DNA from taxonomic groups commonly used for feeding some reptile species such as Mus musculus (common house mouse) and the genus Rattus (rat species) was determined. Conclusion: The 12S-120bp mitochondrial marker used in this case was successful for obtaining sequences from forensic samples; however, the use of any marker for taxonomic assignment depends largely on the information available and the characteristics of each taxonomic group.