UGI External Seminar - Professor Shai Carmi - The Hebrew University of Jerusalem

Abstract: We generated genome-wide data for 33 Ashkenazi Jews (AJ) whose skeletons were recovered in a salvage excavation at the medieval Jewish cemetery of Erfurt, Germany, and were dated to the 14th century. The Erfurt individuals are genetically similar to modern AJ and have substantial Southern European ancestry. However, as opposed to modern AJ, the Erfurt Jews show genetic and isotopic evidence of stratification, likely reflecting origins along a West to East geographic cline. A third of the Erfurt individuals carried the same AJ-specific mitochondrial haplogroup and eight carried pathogenic variants known to affect AJ today. Together with high levels of runs of homozygosity, these observations suggest that the Erfurt community had already experienced the major reduction in size that affected modern AJ. However, the Erfurt bottleneck was more severe, implying substructure in medieval AJ. Together, our results suggest that the AJ founder event and the acquisition of the main sources of ancestry pre-dated the 14th century, while highlighting late medieval genetic heterogeneity no longer present in modern AJ.