Genetic history of Welsh sheep shows migration of ancient Brits

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The genetic history of native Welsh sheep breeds can show us the migration habits of Britain’s historic peoples according to a new study by the Royal Veterinary College, University of London and Aberystwyth University.

The three year research project has mapped the genomic-history of all 18 native breeds of Welsh sheep. As well as providing a look at migration, the research will also help Welsh farmers breed superior sheep by identifying genetic inefficiencies in the animals, helping boost agricultural and economical practices in the country’s farming sector.

Sheep were introduced to the UK during the Neolithic period, but little is known about the history, genetic diversity and relationship of Welsh breeds with other European varieties. This project mapped the genome of 353 individual animals from the 18 native Welsh sheep breeds. This genotyping data was then combined with, and compared to, a set of worldwide breeds previously collected during the International Sheep Genome Consortium project from across Europe, Asia, Australia and Africa.

The findings showed that Welsh sheep share their genes with several other breeds from across Europe but not from Asia, Africa and Australia. Some breeds, such as the Black Welsh Mountain Sheep, saw their genetic history mapped back to Scandinavia, meaning their genetic history is heavily influenced by the sheep brought to Wales by the Vikings. Other sheep, such as the Llandovery White Face, saw its roots stretch back even further to the colonisation of Britain by the Romans.

The study even found one particular breed of sheep, exclusively from the Lleyn peninsula in northwest Wales, can trace its genetics back to a single, small flock of sheep in Galway, Ireland from the early 19th century. This shows that traders and farmers from that part of Ireland came to this area of Wales for agricultural purposes more than 200 years ago.

Beyond human migration, the genetic history and make-up of sheep has importance for the country’s farming economy. Sheep farming is one of the most important areas of the Welsh agricultural sector is, contributing around £230 million to the overall UK economy annually.

Therefore, further understanding the relationships between breeds within Wales, the UK and the rest of Europe will assist breeding strategies at a genetic level. The aim of these strategies is lower costs, increased efficiency, improved livestock health and monitoring of inbreeding that can affect the production of wools, meat and lambing.

Dr Denis Larkin, Reader in Comparative Genomics, who led the research, said: “This whole-genome genotyping has greatly improved our understanding of the genetic structure, origins and migration of Wales’ native sheep, as well as the movement of human populations linked to these processes.

“One of the additional findings was the Welsh breeds did not form a genetically homogeneous group. Instead four genetically different subpopulations have been identified within the 18 native breeds.”

Dr Larkin added: “Our data suggests common ancestry between the native Welsh and various European breeds. But the Welsh breeds are also highly diverse for such a low to moderate population size, forming at least four distinct genetic groups.”

PhD researcher, Sarah Beynon, from Aberystwyth University who performed the research added: “These findings provide the basis for future genome-wide association studies and a first step towards developing genomics assisted breeding strategies in the UK.”