Genetic monitoring of horses in the Czech Republic: A large-scale study with a focus on the Czech autochthonous breeds.

This research involves a comprehensive genetic study of horses in the Czech Republic. A total of 9289 horses were analyzed, concluding that despite previous inbreeding and genetic bottlenecks, some Czech breeds have not suffered significant loss of genetic diversity.

Objective of the Study

• The primary aim of this research was to perform an in-depth genetic monitoring of horse populations in the Czech Republic. This effort represents the largest-scale study of its kind conducted in the region.

Methodology

• Overall, 9,289 animals from 44 different horse populations were examined. This also involved other equids such as Equus przewalskii and Equus asinus.
• Genetic variations among these populations were examined by scanning the animals for 17 different Short Tandem Repeats (STRs), sequences of DNA that occur consecutively and can be used for genetic mapping.

Findings

• A total of 228 distinct alleles (versions of a gene) were identified, with a mean (average) number of 13.4 found per each mapped loci (identified position on a chromosome).
• Allelic richness (a measure of the number of alleles in a gene pool) was highest in three breeds: the Welsh Part Bred, the Camargue, and the Czech Sport Pony. Conversely, the Friesian exhibited the lowest allelic richness.
• Only about nine per cent of the total genetic diversity could be explained by differences between the various populations.
• Genetic distances between various horse breeds were also assessed. For example, a close genetic proximity was found between the Silesian Noriker and the Noriker. The Moravian Warmblood exhibits significant genetic differentiation and distance from the Czech Warmblood.
• Despite past instances of inbreeding and genetic bottlenecks (events that cause a significant reduction in population size), certain breeds such as the Czech-Moravian Belgian Horse, Hucul, Old Kladruber Horse, and Silesian Noriker, were found not to have suffered significant loss of genetic diversity possibly due to genetic drift or low effective population size.
• A NeighborNet dendrogram (a visual diagram mapping genetic similarities between various species) was used to classify breeds. Some breeds (such as the Friesian, Hafling and Merens) were not classified within their usual groups based on standard nomenclature.

Conclusions

• This study provides invaluable insights into the genetic diversity and proximity of horse breeds in the Czech Republic. The findings can inform strategies for breeding and conservation, ensuring the preservation of this diversity for generations to come.