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.