Whole mitochondrial genome diversity in serbian population: phylogenetic and forensic aspects

Abstract

Mitochondrial DNA (mtDNA) is used in forensics for over three decades and is particularly suitable when STR profiling cannot be performed due to the degraded and/or scarce nuclear DNA. Traditionally, mtDNA typing is based on ~600 bp of the hypervariable segments I and II (HVS-I and HVS-II) of the control region (CR, ~1100 bp). Nowadays, it is possible to use variability of complete mtDNAs which enables maximum resolution of distinct maternal lineages. However, the number of complete mitogenomes in reference databases such as EMPOP is still insufficient, and that hampers their wider usage in forensic casework. In order to fill in the gap in the reference database, which, considering Slavic-speaking populations, currently comprises only mitogenomes of East and West Slavs, we present population data for 226 Serbian mitogenomes, representatives of South Slavs from the Balkan Peninsula. We support previous findings on both high levels of genetic diversity in the Serbian population and patterns of genetic differentiation among Serbian and ten studied European populations. However, increased genetic differentiation was observed among Serbian and two European populations (Russians and Poles) with our high resolution data. We demonstrate that the inclusion of indel polymorphisms into analysis contributed towards nearly complete resolution of mtDNA haplotypes (97.1% vs. 86.3% without indels), and that the random match probability was as low as 0.53%. Bayesian skyline analysis of Serbian mitogenomes revealed population expansion after the Last Glacial Maximum and during the Migration period (IV-IX century A.D.). Phylogenetic analysis of the Serbian and relevant West Eurasian haplotypes contributed towards the improvement of the worldwide mtDNA phylogeny to the certain extent, which is essential for the interpretation of the mtDNA casework. Lineages of a putative Balkan origin as well as those shared among Serbian and other European populations were observed.