STRoe deer: A validated forensic STR profiling system for the European roe deer (Capreolus capreolus)

European roe deer (Capreolus capreolus L.) are the most common game species in Europe, hunted for meat and trophies. Forensic investigations involving roe deer poaching may often benefit from an individual identification method to link a suspect to a specific incident. The current paper presents a forensically validated DNA profiling system for European roe deer called “STRoe deer”. This DNA profiling system consists of 12 novel unlinked tetranucleotide short tandem repeat (STR) loci and two sex-specific markers, with an allelic ladder to facilitate accurate genotyping. Validation results demonstrate successful amplification of all 14 loci with as little as 0.05 ng of European roe deer DNA. Species-specificity tests showed that other members of the Cervidae family exhibited partial profiles and non-specific peaks, whereas most members of the Bovidae family showed just non-specific cross-species amplification products. Based on 513 European roe deer samples collected from a population from the Swiss Plateau, probability of identity was 3.1 x 10- 12 and the fixation index of 0.0275 indicated that only weak effects of genetic substructure or inbreeding were present in this population. Three different methods to calculate match probabilities for randomly sampled genotypes resulted in median match probabilities ranging from 1.4 x 10-13 to 2.5 x 10-5. These methods accounted for population structure, occurrence of null alleles or relatedness of the involved individuals. Based on these results, we conclude that STRoe deer is a robust genotyping system that should prove a valuable tool for individual identification and sexing of European roe deer to support criminal investigations.