Individual identification of fox ( Vulpes vulpes) in forensic wildlife investigations

Abstract

In recent casework the relatedness of a group of foxes ( Vulpes vulpes) was questioned, as the manner of their relatedness might indicate the intentional release of several individuals. To this extent a fox-genotyping technique was pursued. 21 microsatellite markers (STRs) designed for individual identification of dogs ( Canis lupus familiaris) were tested on foxes to determine which markers could be amplified reliably and scored unambiguously. For this subset of markers the possibility of multiplex amplification was tested, as were the variability and allele range of these markers. Approximately two third of the tested STRs of which some were combined in multiplex reactions, were amplified and scored readily in foxes. Both the number of alleles and allele range were observed to differ between dogs and foxes for most markers. To understand these differences and their possible effect on the use of these markers the sequence of several alleles was determined. Changes in both flanking regions and repeat structure were identified, however these changes did not influence the use of the STRs for identification purposes. After genotyping the case samples with this subset of markers a conclusion was formulated expressing the likelihood of a familial relationship of all individual foxes. The obtained genotypes are stored to compare with biological material found if a suspect of an intentional release were to be found.