Biology session

After several decades of absence, the grey wolf (Canis lupus) started recolonizing its former territories in Hungary in the beginning of the 21st century. First the Aggtelek National Park and then the areas of the Bükk National Park were invaded by them. Due to the intense presence of mankind, wolves are forced to share great areas of land with humans, thus potentially leading to several conflicts. From the wolves' perspective, it means the decimation of domestic livestock. As far as humans are concerned, these conflicts may manifest in the illegal hunting of them and trading with their products. Indirectly, people are responsible for hybridization as well, because of inappropriate canine husbandry and as a result, the genetic deterioration of wolf population. When facing such instance, it should be examined whether the perpetrator/victim is a wolf, a dog, or a hybrid. Many genetic studies trying to get the answer for this question. The aim of my study is to find an appropriate genetic method to distinguish wolves, dogs, and their hybrids, which can be used in a forensic application as well.

For this research, altogether 36 samples (hair, skin, faecal matter, saliva, and purified DNA) from wolves, hybrids as well as from Czechoslovakian wolfhound were collected. For the comparative canine database DNA samples from Hungarian dog populations were used (haplo- and genotypes were partially available). After DNA isolation, uniparental (mitochondrial control region, Y-chromosome microsatellites and SRY) and biparental (autosomal microsatellites) markers were amplified by polymerase chain reaction. Based on the point mutation pattern of the control region determined by sequencing analysis, haplotypes were grouped using PoPART. Microsatellite markers amplified with fluorescently labelled primers were detected by capillary electrophoresis. Genetic profiles based on the detected alleles were analysed using Structure 2.3.4 and were grouped by the Bayes theorem.

The mitochondrial control region (HV1) haplotypes were successfully determined from the examined samples, these sequences were uploaded to the GenBank database. We did not find similar point mutation pattern between wolves and dogs. In contrary, the analysis of nuclear markers was not always successful. This is partially because in some cases only a little amount of degraded biological samples were available, and because of the suboptimal nature of the investigative method regarding the Y-chromosomal markers. However, based on the detected microsatellite allele distribution difference was shown between wolf and dog groups, further markers and more wolf samples should be involved.

Overall, our previous results support that simultaneous application of large number of genetic markers – meeting with the standards of the forensic application criteria –, could be adequate to determine the precise taxonomic origin of a questionable sample with appropriate statistical probability.