The conservation of genetic diversity in Turkish native horse breeds

Abstract

In the last two decade, the loss of animal genetic resources, as an inevitable result of the decrease both in the number of species and in the population size, has become an important issue and many countries have prepared their own action plan concerning the conservation strategies on the basis of FAO’s global management program. Although, wild species generally have been prioritized in the conservation studies, domesticated animals should also be considered as a part of the present biodiversity. Identifying genetic compositions of species is the first step of subsequent breeding programs and conservation studies. The domestication events of several animal species namely sheep, cattle and goat were carried out in Anatolia. Even though the Anatolian peninsula is located within several immigration and trade routes between the east and the west, and horses were used for transportation and warfare, there have been no studies concerning the origins and the evolutionary processes of Turkish native livestock horse breeds based on DNA markers. In this study, 319 base pairs of the mitochondrial DNA (mtDNA) D-loop region of 317 horse samples representing five phenotypically distinct Turkish native horse breeds was analyzed, genetically characterized and to set up the basis for a conservation program. According to the number of variable sites identified within D-loop region, Turkish native horse breeds have high haplotype, and low nucleotide diversities. In addition, because of the high motility of horses, inappropriate horse trading habits, and lack of proper breeding strategies for horses in Turkey, significant genetic separations were not observed among horse breeds. A phylogenetic network constructed based on mtDNA sequences including various Turkish native livestock horses and GenBank sequences representing seven previously published haplogroups showed that Turkish horse breeds clustered into these seven clades and one additional unique clade which could be named as an eighth haplogroup. mtDNA analysis of Turkish horses also indicates the presence of many ancient maternal lineages within.