| Summary: | In this thesis, Y-chromosomal analysis based on 50 biallelic markers was applied to investigate three scenarios of horse breeding in four Russian horse breeds. In total, Y-chromosomal haplotypes of 79 stallions were determined in order to draw genealogical conclusions about their paternal lines. The first scenario deals with Orlov Trotters, who are a thoroughly bred breed and trace back to one single founding stallion. All but two of the 13 Individuals studied had the same haplotype. The common descent of almost all examined animals from this one founder stallion was thus confirmed. Furthermore, a crossbreeding that was not documented in the pedigree was discovered. Russian Trakehners, a breed with an exceptionally long and eventful history, formed the second scenario. The haplotypes detected in the 33 animals corroborated the influence of well- documented stallion lines from widely used refiner breeds, such as English Thoroughbreds and Arabian. In addition, a few pedigree errors were uncovered. The errors occurred, similar to the observation in Orlov Trotters, several generations back in time. Mezen horses and Yakuts, two extensively bred landraces, resulted in the third scenario. The 33 animals studied from those breeds showed a broad spectrum of haplotypes. This could be explained by the less pronounced selection on stallions in breeding practice. However, crossbreeding with modern breeds, as noted in literature, could also be confirmed. Particular attention was paid to the potential and limitations of Y-chromosomal haplotype typing using the KASP ™ technology. With this strategy it was possible to screen many samples for Y-haplotypes with moderate technical and financial effort. However, a limitation of the method namely the presence of private haplotypes that could not be further investigated, became evident. These haplotypes need to be characterized in future work by the more complex and expensive NGS technology. Combining these two approaches, which means sequencing appropriately selected individuals ...
|
|---|