Medieval manuscript sheeppox DNA traces a livestock virus across millennia
Researchers found sheeppox DNA in medieval parchment, using manuscripts and Bronze Age sheep teeth to track the virus’s long history.
By James Whitfield · Staff Writer
2 min read
Researchers have found medieval manuscript sheeppox DNA in parchment from European collections, including the York Gospels, giving scientists genetic material to examine a livestock virus over thousands of years. The findings matter because sheeppox can spread quickly through flocks, cause high mortality among young animals and reduce wool, meat and milk output, according to Discover Magazine.
The University College Dublin-led international team reported the work in Science Advances, according to Phys.org and Discover Magazine. It analyzed parchment from the York Gospels, the Corpus Glossary at Corpus Christi College, Cambridge, and other medieval manuscripts from Britain and continental Europe.
How did medieval manuscripts preserve sheeppox DNA?
Parchment was made by preparing the hides of livestock, including sheep, goats and cattle. The researchers said fragments of animal and pathogen DNA could remain in those skins after they were turned into writing material, making centuries-old pages a record of an animal’s health at the time it died.
Several pages in some individual manuscripts carried sheeppox virus DNA, Phys.org reported. Researchers said that pattern indicates infected animals were used to make at least some of the parchment, though the genetic evidence does not establish how infections spread among herds or during production.
The results also included viral DNA found on calfskin and goatskin parchment. According to Phys.org and Discover Magazine, the team offered two possible explanations: uncommon cross-species infections or contamination during the manufacture of parchment. The available evidence does not distinguish between those possibilities.
What do the manuscripts add to sheeppox history?
The manuscript samples were part of a wider comparison that included viral genetic material from Bronze Age sheep teeth recovered at ancient pastoralist settlements on the Eurasian steppe. Together, the evidence allowed researchers to reconstruct more than 3,500 years of sheeppox virus evolution, Phys.org reported.
Louis L’Hôte, the study’s lead author and a University College Dublin doctoral candidate, said the results show sheeppox has affected Eurasian sheep herds for at least three and a half millennia. The team also reported that the virus’s genome appeared relatively stable over the past several millennia, according to Phys.org.
The study illustrates a way archives may contribute to research on animal disease. L’Hôte said libraries and archives could retain genetic traces of earlier livestock outbreaks, while supervising author Kevin G. Daly said parchment preserves both cultural history and evidence of disease in medieval livestock, according to University College Dublin.
This story draws on original reporting from Ars Technica.