Genetic diversity of Akhal-Teke horse bred in Italy assessed by molecular markers

The Akhal-Teke is a horse breed of Turkmen origins, from the southern region of the Turkmenistan modern country. They are well known for their speed and endurance on long marches. These "golden-horses" are adapted to severe climatic conditions and are thought to be one of the most ancient surviving horse breeds. Since 1998 the Laboratory of the Department of Animal Science of the University of Milan tested this rare horse breed in Italy for parentage control using both classical markers (blood groups and protein polymorphisms) and microsatellites. During this period blood samples from 102 horses were collected. In the present study, the mitochondrial D-loop DNA region (mtDNA) genetic variability and haplotypes relationship of Akhal-Teke horses reared in Italy were investigated. Twenty-two unrelated horses belonging to different maternal lineage from our database were chosen. The mtDNA was extracted using standard procedures. A 379 bp fragment of horse mtDNA was amplified and sequenced. The obtained sequences were aligned among themselves and with the complete horse mtDNA sequence (GenBank# X79547), using the CLUSTALX software. Diversity parameters, haplotype diversity (Hd), nucleotide diversity (p) and average number of nucleotide differences (k) were calculated using DnaSP 5.1 software. Horse sequences from GenBank database were used for relationship investigations. Median-joining network and mismatch analysis were calculated using NETWORK 4.5.0.1. Twelve haplotypes were found in the Akhal-Teke horses reared in Italy. Hd, p and k values were 0.938, 0.021 and 6,448 respectively, indicating a good variability. The comparison with database sequences showed the presence of seven haplogroups.