Population Structure and Genetic Diversity Among Shagya Arabian Horse Genealogical Lineages in Bulgaria Based on Microsatellite Genotyping.
Abstract: The Shagya Arabian horse breed was created to address the need of Imperial Hussars (Hungarian light horsemen) for a horse with the intelligence, essential characteristics, and endurance of the Arabian breed, but also of a bigger size and having a better weight-carrying capacity and jumping ability. The present study aimed to explore the genetic variability and population structure of the uninvestigated Shagya Arabian horse population in Bulgaria based on genotyping at 15 equine microsatellite markers. A total of 140 horses belonging to six genealogical lines (Dahoman, Gazal, Ibrahim, Kuhailan Zaid, O'Bajan, and Shagya) were included in the survey. Genetic distances, analysis of molecular variance, principal coordinates analysis, and a Bayesian method were applied. The mean number of alleles in the individual subpopulations ranged from 3.67 in the Shagya to 5.13 in the Ibrahim sire line. The F index was negative or close to 0 for the entire population and was -0.202. The overall was 0.014, indicating a low level of genetic differentiation between the subpopulations. The results of the principal components and the STRUCTURE analysis showed some level of admixture among the subpopulations in almost all genealogical lines. However, structural analysis also indicated a genetic similarity between the Ibrahim, Kuhailan Zaid, and Shagya lineages, while it showed a completely different genetic profile regarding the other three sire lines. Due to the higher admixture and the discovery of more distinct genetic clusters, it can be assumed that there is a higher gene flow from one lineage to another in the Shagya Arabian horse population in Bulgaria and that there is sufficient genetic variability and diversity to suggest adequate measures for preserving this rare breed. In addition, this study may highlight the risk of the loss of gene diversity in this population and help to implement suitable breeding programs to preserve genetic diversity.
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Overview
This study examined the genetic diversity and population structure of the Shagya Arabian horse population in Bulgaria by analyzing 15 microsatellite markers across six genealogical lineages.
The research found a generally low genetic differentiation between lineages and evidence of gene flow among them, indicating sufficient genetic variability but a need for conservation efforts to maintain this rare breed.
Introduction and Objectives
The Shagya Arabian horse breed was originally developed to meet the demands of Imperial Hussars for horses combining Arabian traits with larger size, enhanced endurance, and better jumping and weight-carrying abilities.
The breed’s genealogy consists of several sire lines or ancestral lineages, which have not been genetically analyzed in Bulgaria before this study.
The goal was to investigate the genetic variability among six different genealogical lineages of Shagya Arabian horses in Bulgaria using microsatellite genotyping to better understand their population structure and genetic diversity.
Materials and Methods
Sample: 140 horses representing six genealogical lines—Dahoman, Gazal, Ibrahim, Kuhailan Zaid, O’Bajan, and Shagya.
Marker Type: 15 equine microsatellite markers, commonly used for genetic diversity and population structure studies due to their high variability.
Analyses Conducted:
Calculation of allele numbers per lineage to estimate genetic diversity.
F-statistics (F index) to determine inbreeding and population differentiation.
Pairwise genetic distances and analysis of molecular variance (AMOVA) to assess differentiation among lineages.
Principal Coordinates Analysis (PCA) to visualize genetic relationships between lineages.
Bayesian clustering method using STRUCTURE software to detect population structure and admixture.
Key Findings
Allelic Diversity: The mean allele number per lineage ranged from 3.67 (Shagya) to 5.13 (Ibrahim), indicating some variation in genetic diversity across lineages.
Inbreeding and Differentiation:
The F index was close to zero or negative (-0.202 overall), suggesting low inbreeding or possibly some outbreeding.
The overall F_ST was 0.014, reflecting very low genetic differentiation among lineages, meaning they share much genetic material.
Genetic Structure and Admixture:
PCA and STRUCTURE analysis revealed admixture among almost all genealogical lines, indicating gene flow between lineages.
The other three lineages (Dahoman, Gazal, and O’Bajan) displayed distinct genetic profiles, separate from the above group.
Interpretation and Implications
The low genetic differentiation implies a shared genetic pool among the Shagya Arabian horses in Bulgaria, with ongoing gene flow between lineages.
The detectable admixture suggests the lineages are not fully isolated but interbreeding occurs, which helps maintain genetic diversity.
Given the Shagya Arabian horse is a rare breed, the observed genetic variability is encouraging for breed preservation.
However, because of the risk of genetic diversity loss over time, the study recommends:
Implementing structured breeding programs that monitor and maintain genetic variation.
Carefully managing gene flow to avoid inbreeding depression and loss of unique lineage traits.
Conclusion
This study provides the first insight into the genetic structure of Shagya Arabian horses in Bulgaria, highlighting a relatively rich gene pool across different genealogical lineages despite some differentiation.
The findings support future conservation strategies aimed at preserving the breed by maintaining its genetic health and diversity through informed breeding management.
Cite This Article
APA
(2025).
Population Structure and Genetic Diversity Among Shagya Arabian Horse Genealogical Lineages in Bulgaria Based on Microsatellite Genotyping.
Vet Sci, 12(8), 776.
https://doi.org/10.3390/vetsci12080776
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