Whole-loop mitochondrial DNA D-loop sequence variability in Egyptian Arabian equine matrilines.
Abstract: Egyptian Arabian horses have been maintained in a state of genetic isolation for over a hundred years. There is only limited genetic proof that the studbook records of female lines of Egyptian Arabian pedigrees are reliable. This study characterized the mitochondrial DNA (mtDNA) signatures of 126 horses representing 14 matrilines in the Egyptian Agricultural Organization (EAO) horse-breeding program. Results: Analysis of the whole D-loop sequence yielded additional information compared to hypervariable region-1 (HVR1) analysis alone, with 42 polymorphic sites representing ten haplotypes compared to 16 polymorphic sites representing nine haplotypes, respectively. Most EAO haplotypes belonged to ancient haplogroups, suggesting origin from a wide geographical area over many thousands of years, although one haplotype was novel. Conclusions: Historical families share haplotypes and some individuals from different strains belonged to the same haplogroup: the classical EAO strain designation is not equivalent to modern monophyletic matrilineal groups. Phylogenetic inference showed that the foundation mares of the historical haplotypes were highly likely to have the same haplotypes as the animals studied (p > 0.998 in all cases), confirming the reliability of EAO studbook records and providing the opportunity for breeders to confirm the ancestry of their horses.
Publication Date: 2017-08-31 PubMed ID: 28859174PubMed Central: PMC5578668DOI: 10.1371/journal.pone.0184309Google Scholar: Lookup
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- Journal Article
Summary
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The research article focuses on the genetic analysis of Egyptian Arabian horses, investigating their mitochondrial DNA (mtDNA) signatures. It sets out to validate the studbook records of these horse breeds and gain a better understanding of their genetic lineage.
Objective of the Study
- The objective of the study was to explore the accuracy of the studbook records of Egyptian Arabian horses using mtDNA signatures. The researchers used mtDNA to investigate the lineage of 126 horses from 14 matrilines in the Egyptian Agricultural Organization’s (EAO) horse-breeding program.
Research Methodology
- The researchers analysed the complete D-loop sequence in the mtDNA. They found this method to be more informative than studying only the hypervariable region-1 (HVR1).
- They discovered 42 polymorphic sites indicative of ten different haplotypes when they analyzed the entire D-loop sequence. In contrast, an analysis focusing merely on the HVR1 revealed 16 polymorphic sites indicative of nine haplotypes.
Findings of the Study
- Most of the haplotypes discovered in the EAO horses belonged to ancient haplogroups, suggesting that these horses originated from a broad geographical area over thousands of years. The researchers also identified a novel haplotype, indicating some unknown or unique genetic lineage.
- Historical family lines of horses shared common haplotypes, some of them grouped in the same haplogroup despite being from different strains. This implies that the traditional classification into EAO strains doesn’t always correspond to distinct maternal genetic lineages.
Conclusion
- The study concludes that the founder mares of historical haplotypes are highly likely to have the same haplotypes as the present-day horses in the study. This comparison provides a high confidence level (p > 0.998) in the accuracy of EAO’s studbook records.
- By confirming the reliability of the studbook records, the results offer horse breeders an opportunity to authenticate the lineage of their animals accurately.
Cite This Article
APA
Hudson W.
(2017).
Whole-loop mitochondrial DNA D-loop sequence variability in Egyptian Arabian equine matrilines.
PLoS One, 12(8), e0184309.
https://doi.org/10.1371/journal.pone.0184309 Publication
Researcher Affiliations
- William Hudson MD, Hudson Cardiology P.C., Atlanta, Georgia, United States of America.
MeSH Terms
- Agriculture
- Animals
- DNA, Mitochondrial / genetics
- Egypt
- Haplotypes / genetics
- Horses / genetics
- Mitochondria / genetics
- Pedigree
- Phylogeny
Conflict of Interest Statement
I can also confirm that the disclosure that WMH is an Arabian horse breeder does not alter my adherence to all PLOS ONE policies on sharing data and materials.
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Citations
This article has been cited 4 times.- Nikbakhsh M, Varkoohi S, Seyedabadi HR. Mitochondrial DNA D-loop hyper-variable region 1 variability in Kurdish horse breed. Vet Med Sci 2023 Mar;9(2):721-728.
- Agbani A, Aminou O, Machmoum M, Germot A, Badaoui B, Petit D, Piro M. A Systematic Literature Review of Mitochondrial DNA Analysis for Horse Genetic Diversity. Animals (Basel) 2025 Mar 20;15(6).
- Muttaqin Z, Sartika T, Saputra F. Genetic diversity of Gallus sp. in Southeast Asia based on d-lopp: In silico study. J Adv Vet Anim Res 2023 Dec;10(4):817-819.
- Machmoum M, Badaoui B, Petit D, Germot A, El Alaoui MA, Boujenane I, Piro M. Genetic Diversity and Maternal Phylogenetic Relationships among Populations and Strains of Arabian Show Horses. Animals (Basel) 2023 Jun 17;13(12).
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