Mitochondrial Control Region Database of Hungarian Fallow Deer (Dama dama) Populations for Forensic Use

Abstract

The evidential value of an mtDNA match between biological remains and their potential donor is determined by the random match probability of the haplotype. This probability is based on the haplotype's population frequency estimate. Consequently, implementing a population study representative of the population relevant to a forensic case is vital to correctly evaluating the evidence. The emerging number of poaching cases and the limited availability of such data emphasizes the need for an improved fallow deer mtDNA population databank for forensic purposes, including targeting the entire mitochondrial control region. By sequencing a 945-base-pair-long segment of the mitochondrial control region in 138 animals from five populations in Hungary, we found four different haplotypes, including one which had not yet been described. Our results, supplemented with data already available from previous research, do not support the possibility of determining the population of origin, although some patterns of geographical separation can be distinguished. Estimates of molecular diversity indicate similarly low mtDNA diversity (Hd = 0.565 and π = 0.002) compared to data from other countries. The calculated random match probability of 0.547 shows a high probability of coincidence and, therefore, a limited capacity for exclusion. Our results indicate that despite the overall low genetic diversity of mtDNA within the Hungarian fallow deer samples, a pattern of differentiation among the regions is present, which can have relevance from a forensic point of view.

Keywords: control region (CR); fallow deer (Dama dama); forensic genetics; mitochondrial DNA (mtDNA); population study; random match probability; wildlife crime.

Figure 1

Comparison of the polymorphic sites of the mitochondrial control region (CR) to the reference sequence (NC_020700) based on the length of the investigated segment in introduced fallow deer stocks. Ref: previous studies and sequences downloaded from GenBank (GB). Color codes: polymorphic sites per 10 base pairs. N: number of sequences. O: number of countries the samples originated from. S: number of variable sites. k: number of haplotypes. Ref¹: [12]; Ref²: [11]; Ref³: [9]; Ref⁴: [10]; GB¹: MK473448-50; GB²: ON321840-41; GB³: OQ535577-79; GB⁴: OR220344-89; GB⁵: OR232305-17; ni: no information.

Figure 2

The distribution of haplotypes Hun1–Hun6 of the fallow deer populations studied in Hungary in six regions. n: sample size. *: seven and six sequences from populations SW and SE, respectively, originated from a previous study [9], **: sequence data originated from a previous study [10].