The objective - To identify Zemaitukai mtDNA D-loop region and genetic relationships between Zemaitukai and some other breeds based on mtDNA sequence variation. Methods - To perform a phylogenetic analysis of 10 Zemaitukai, mtDNA D-loop 49 horses in the 20 different horse breeds sequence were included from GenBank (http://www.ncbi.nlm.nih.gov/GenBank). DNA was extracted from hair roots using the DNEasy® Tissue Kit (Qiagen). 1,280 bp fragment of mtDNA D-loop were amplify out in PTC-100™ termocycler. Amplified products were sequenced on a LI-COR® 4200S-2 automated sequencer. Sequencher v 4.1.4. software package was used to generate the actual DNA sequence for each of the animals. Multiple alignments of sequences were performed with CLUSTAL X 1.8 (Thompson et al., 1997). The Neighbor-joining tree (Saitou and Nei, 1987) of mtDNA sequences was constructed from Jukes-Cantor distances, performed on the pairwise deletion using the MEGA software (Kumar et al., 1993). Results –Within Zemaitukai breed 19 polymorphic sites were detected and 6 haplotypes. At the individual level 4 zemaitukai haplotypes were private to one individuals, 1 haplotype-between 2 individuals and 1 haplotype was shared between 4 individuals. On the Neighbor-joining tree showed one Zemaitukai haplotype closer genetic relationships to the Icelandic and to the Norwegian Fiord horse haplotypes. Zemaitukai breed formed a separate branch with the ancient DNA haplotype. The phylogenetic analysis reflects the presence... [to full text]