Periodic Reporting for period 1 - ENDANGEREDHORSES (Conservation genomics of endangered indigenous European horse breeds)
Reporting period: 2017-03-15 to 2019-03-14
Since the Industrial revolution, horses have diminished in terms of their importance. However, there are several thousands of horse breeds today. Especially in Europe, several of these horse breeds are iconic and representative of certain regions like the Camargue or the Friesian horses. Certain breeds used for racing or dressage can reach a very high market price. However, very little is known about their history and their origin. Furthermore very little is known about the state of their genetic diversity and whether long-term conservation can be achieved.
The goal of this project was to sequence a large number of horses breeds and ideally various individuals per breed. The goal was to reconstruct population histories as well as try to identify some genomic targets for selection.
In general, we find that horse breeds can be classified into three categories: 1) highly related to Arabian horses 2) having little or no Arabian ancestry 3) being a mixture of the first two categories. We find that the most divergent horse breeds are found in Asia followed by Central Asia and followed by northern Europe. We find that these horses have the highest genetic diversity indicating that they are more ancient populations and not Arabian horses which underwent selection. Furthermore, we showed that certain horse breeds have a critical paucity of genetic diversity due to continuous inbreeding.
The technique used to infer the level of inbreeding as well as remaining genetic diversity was presented by Gabriel Renaud at the 8th International Symposium on Biomolecular Archaeology (ISBA) in 2018 And was recently accepted in Genetics: Gabriel Renaud, Kristian Hanghøj, Thorfinn Korneliussen, Eske Willerslev, and Ludovic Orlando. Joint estimates of heterozygosity and runs of homozygosity for modern and ancient samples. This was accepted for publication in Genetics, 2019. The main paper describing the results of the different horse breeds is being drafted as we speak.
Our work on horse breeds highlights the uniqueness of certain horse breeds especially those with very low Arabian ancestry. Horse breeds like the Icelandic horses will garner additional attention in the future and will probably result in further economic downfalls to increased tourism and increased interest in such horse breeds.