Museum samples

Another focus of the Pleistocene Genomics Lab is the analysis of historical museum specimens. These specimens allow the opportunity for genetic investigation of endangered, rare, and even recently extinct animals, for which fresh tissue samples would be difficult or even impossible to obtain. The preservation methods and long term storage of these biological specimens is associated with DNA degradation and chemical modification, presenting similar challenges to the genetic analysis of ancient Pleistocene-age samples.

European bison

A recent study run in collaboration with Karolina Wecek and Jacek Szymura at the Jagiellonian University in Poland, and Prof. Michi Hofreiter’s Lab in Potsdam, investigated historical museum samples of European bison (see Wecek et al. 2017). European bison became extinct in the wild around the turn of the last century, with only a handful of individuals surviving in captive collections. From these, a captive breeding herd was established to preserve the bison, eventually allowing their re-release into the wild. We sequenced genomes from historical bison, including two individuals form the original founding herd, as well as their modern descendants.

This museum specimen (left) is one of the original founding herd from which all modern bison (right) are descended. By applying the sample methodologies we used for Pleistocene age samples, we were able to sequence the genome of this founding individual and compare it to modern descendants. See Wecek et al. 2017.

Our analyses provided many new insight into bison evolution. We found that bison in Western Europe and those in the Caucasus Mountains, previously recognised as different “subspecies” did form distinct populations, but that these populations had intermixed extensively prior to their extinction in the wild. Modern bison are managed as two genetic lines: one descending from Western European founders (L line), and the second descending from Western European and Caucasian founders (LC line). Using genome data from historical specimens as a point of reference, we were able for the first time to accurately pinpoint regions of Caucasian and Western European ancestry in a modern LC line bison.

Chromosomal ancestry map of a modern LC line bison. Chromosomes 1 to 29 are represented as horizontal lines, with blue sections inherited from Western European bison, and yellow sections inherited from Caucasian bison. See Wecek et al. 2017.

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