Johannes Krause is Professor for Paleogenetics at the Eberhard Karls University in Tuebingen, Germany. He is specialized in ancient DNA research. Previous to his current academic appointment, Dr. Krause worked as a PhD student and as a postdoctoral fellow under Dr. Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Despite his strong focus on evolutionary genetics and ancient DNA research, his work includes a large variety of topics ranging from method development in high-throughput DNA sequencing and innovative targeted DNA enrichment strategies, to phylogenetics of Pleistocene megafauna such as woolly mammoth and cave bear, and complete genome-wide studies of Pleistocene archaic humans such as the Neanderthal.
Dr. Krause’s research pioneered the analysis of nuclear DNA from fossil human remains by analyzing the FOXP2 language gene in Neandertals. His work furthermore introduced the use of molecular properties such as DNA damage patterns that are unique to ancient DNA as a method of authenticating ancient molecular data. This novel method allowed retrieving the first authentic mitochondrial DNA genome of a Pleistocene anatomically modern human, thus opening a new field of ancient human genetic research that had not yet been attempted due to the threat of modern human contamination. Dr. Krause’s work on the discovery of a new Siberian hominin in 2010, the Denisovan, garnered worldwide acclaim, with press and media coverage in major newspapers and television. This work represents the first identification of a new hominin, which was made possible solely from molecular data. The reconstructed draft genomes of the Neandertal and Denisovan provide evidence of gene flow into modern human populations putting to rest former theories about human evolutionary history. Dr. Krause’s team recently demonstrated the application of DNA capture techniques and high-throughput DNA sequencing to the reconstruction of complete ancient pathogen genomes using Yersinia pestis isolated from victims of the Black Death. The Black Death genome revealed a medieval origin of all currently circulating human pathogenic strains for which full genomic data are available.
The Genome of The Black Death
Genome wide data from ancient microbes may help to understand mechanisms of pathogen evolution and adaptation for emerging and re-emerging infectious disease. Using high throughput DNA sequencing in combination with targeted DNA enrichment we have reconstructed the ancient genome of Yersinia pestis from skeletons securely dated to the Black Death pandemic from the East Smithfield cemetery in London, England, 1348 – 1350. Phylogenetic analysis indicate that the ancient organism is ancestral to most extant Y. pestis strains and falls very close to the ancestral node of human infectious Y. pestis that had their genome sequenced. Temporal estimates suggest that the Black Death of 1346 – 1351 was the main historical event responsible for the introduction and worldwide dissemination of currently circulating Y. pestis strains pathogenic to humans, and further indicates that contemporary Y. pestis epidemics have their origins in the medieval era. Comparisons against modern genomes reveal no unique derived positions in the medieval organism, suggesting that the perceived increased virulence of the disease during the Black Death may not have been due to bacterial physiology. These findings support the notion that factors other than microbial genetics, such as environment, vector dynamics, and host susceptibility should be at the forefront of discussions regarding emerging Y. pestis infections.
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