phylogenetic and genetic analysis of d-loop and cyt-b region of mtdna sequence in iranian sistani, sarabi and brown swiss cows

cattle have an important role in primary human civilization, so molecular studies for more accurate recognition of their origin are effective to identify unknown historical aspects. cattle can be divided in to 2 main groups including bos tuarus and bos indicus. both types of cattle can be found in iran; therefore study of their origin has particular importance. the aim of this study was to investigate the nucleotide sequences of cytochrome-b (cyt-b) and hvr1&2 loci of d-loop gene region in mitochondrial dna of sistani, sarabi and brown swiss breeds of cattle. twenty blood samples of each breed, from non-relative individuals were obtained from blood bank of animal science department of faculty of agriculture, ferdowsi university of mashhad. the dna content of sample was extracted based on the guanidinium thiocianate-silicagel method. polymerase chain reaction with specific designed primers was performed to amplify cyt-b and hvr 1&2 loci with 751 and 701 bp lengths, respectively. sequencing of amplified cyt-b and hvr 1&2 loci were done based on sanger method by automatic sequencer machine (abi 3130). nucleotide diversity in brown swiss, sarabi and sistani breeds were estimated 0.0037, 0.0024 and 0.0029, respectively. sequences of cyt-b and hvr 1&2 were register in national center for biotechnology institute due to nucleotide differences. results of phylogenetic test using upgma for both loci showed that sarabi and sistani breeds are belonging to first group and brown swiss breed to other group.