PCR-RFLP analysis of mitochondrial DNA cytochrome b gene among Greek horse breeds

Abstract

PCR was used to investigate the genetic differentiation and phylogenetic relationships among five Greek horse breeds at the mitochondrial DNA level. Specifically, a 1350-bp segment comprising the entire cytochrome b gene of mitochondrial DNA was amplified and subsequently screened for RFLPs. Six out of ten restriction endonucleases were found to detect variability, and nine different haplotypes were observed, all belonging to the same phylogenetic assemblage. Haplotype-1 was the most common and possessed the highest frequency in all five breeds. The average values of the observed interpopulation and intrapopulation diversity among breeds were similar (mean = 0.30% and 0.27%, respectively). The results obtained contrast with the theory of a separate origin for Greek horse breeds and indicate an extensive admixture among them. This is also the case with the Skyros pony. Finally, the genetic relationships among breeds suggested by mtDNA data were in accordance with RAPD data.