Genetic and isotopic analyses of medieval skeletons (1150–1349) at St. Peter’s churchyard, Berlin/Cölln, Germany

The medieval market Berlin, nucleus and starting point of what eventually became Germany's capital, was mirrored by another medieval settlement named Cölln (Lat. colonia) on the opposite side of the Spree River. In Cölln, St. Peter's cemetery was in use from about 1150-1717. In this study we investigated individuals from the earliest graves of this cemetery regarding their geographic origin using genetic analyses on bones and teeth as well isotopic analyses on dental enamel. Genetic analysis of 96 individuals was done for 16 autosomal STRs as well as the amelogenin marker for sex determination. We identified 54 unrelated males, who were typed for 27 Y-chromosomal STRs and assigned to 12 different Y-haplogroups. The Y-haplogroup distribution of St. Peter's showed a high similarity to the population of present-day Germany with high amounts of both R1a (31.5 %) and R1b (44.4 %) as well as I1 (11.1 %) and I2a (7.4 %). Geographic ancestry prediction, using AMOVA analysis, revealed a high genetic similarity between the populations of St. Peter's and the present-day German population. Significant differences could be detected for neighboring western and eastern European populations. MtDNA typing for all 96 individuals using coding region SNPs demonstrated a characteristic European distribution with haplogroups H (46.9 %), U (17.7 %), T (12.5 %), J (7.3 %) and K (8.3 %). Further typing for 48 individuals was done by sequencing the full mtDNA control region, revealing only trace amounts of Slavic-associated haplogroups. The strontium and oxygen isotope analysis of 66 of the earliest graves showed that most individuals came from the Berlin-Brandenburg area and the adjacent regions, with signs of migration limited to a few individuals.