The Lusitano horse maternal lineage based on mitochondrial D-loop sequence variation

Area of Science:

• Genetics
• Animal Science
• Evolutionary Biology

Background:

• Mitochondrial DNA (mtDNA) analysis is crucial for understanding equine population genetics and domestication history.
• The Lusitano horse breed, originating from the Iberian Peninsula, has a rich history intertwined with other Iberian horse populations.

Purpose of the Study:

• To analyze the genetic diversity and phylogeographic structure of Lusitano founder mares using mitochondrial D-loop sequences.
• To compare Lusitano mtDNA haplotypes with other equine breeds to infer domestication patterns and origins.

Main Methods:

• Sequencing of the mitochondrial D-loop region (408 bp) from 145 Lusitano founder mares.
• Analysis of haplotype diversity, distribution, and frequency.
• Phylogenetic comparison with existing equine mtDNA sequences from various breeds.

Main Results:

• A total of 27 distinct haplotypes were identified in the Lusitano population, with unequal distribution and a significant proportion of rare variants.
• Four main haplotype clusters were observed within the Lusitano breed.
• A substantial portion of Lusitano, Pura Raza Española, and Sorraia sequences (50.9%) clustered within a specific group (Cluster A), characteristic of Iberian and North African breeds.
• Cluster A exhibited a phylogeographic structure and star-like formation, suggesting a center of origin.

Conclusions:

• The genetic data support the hypothesis of multiple equine domestication events across different regions and time periods.
• The prevalence of Cluster A haplotypes in Iberian breeds points towards the Iberian Peninsula as a significant center for horse domestication.
• The findings contribute to understanding the evolutionary history and genetic distinctiveness of the Lusitano horse.