The Complete Mitochondrial DNA Sequence of the Domestic Sheep (Ovis aries) and Comparison with the Other Major Ovine Haplotype

Abstract

The complete mitochondrial DNA (mtDNA) molecule of the domestic sheep, Ovis aries, was sequenced, together with part of the mtDNA of a specimen representing the other major O. aries haplotype group. The length of the complete ovine mtDNA presented is 16,616 nucleotides (nt). This length is not absolute, however, due to heteroplasmy caused by the occurrence of different numbers of a 75-nt-long tandem repeat in the control region. The sequence data were included in analyses of intraspecific ovine molecular differences, molecular comparisons with bovine mtDNAs, and phylogenetic analyses based on complete mtDNAs. The comparisons with bovine mtDNAs were based on the central domains of the ovine control regions, representing both major ovine haplotype groups, and the corresponding domains of Bos taurus and B. indicus. The comparisons showed that the difference between the bovids was 1.4 times greater than the intraspecific ovine difference. These findings suggest that the strains of wild sheep from which domestic sheep originated were more closely related than were the B. primigenius subspecies which gave rise to B. indicus and B. taurus cattle. Datings based on complete mtDNAs suggest that the bovine and ovine lineages diverged about 30 million years before present. This dating is considerably earlier than that proposed previously.

Haplogroup relationships between domestic and wild sheep resolved using a mitogenome panel

“…Both the mouflon (O. musimon) and Argali wild sheep (O. ammon) carried four copies of a 75 bp repeat, which discriminated them from Urial (O. vignei), and contained one 75 bp repeat followed by four 76 bp repeats (Table 1). The identity of each translation start and stop codon and the order of genes from the ovine mtDNA has been described previously (Hiendleder et al, 1998). The order and features of the 16 mitogenomes were found to be the same, with the notable addition of a complete stop codon (TAA) in the ND3 gene in two Urial sheep (O. vignei h75, h76).…”

“…In previous studies, partial mtDNA sequences have been used to show the Urial and Argali are highly unlikely to be the progenitor of domestic sheep (Hiendleder et al, 1998(Hiendleder et al, , 2002Wu et al, 2003;Chen et al, 2006;Tapio et al, 2006;Meadows et al, 2007), however the relationship between wild and domestic sheep was revisited in this study for three reasons. First, the relationship between wild species remains unresolved, as a number of different phylogenies have been reported (Hiendleder et al, 2002;Bunch et al, 2006;Meadows et al, 2007).…”

“…Mitochondrial DNA sequencing Supplementary Table 1 describes the primer pairs designed using ovine reference sequence AF010406 (Hiendleder et al, 1998), which were employed to amplify the 18 fragments of the mt. PCR products from the 10 domestic and 6 wild animals were produced using the conditions of Meadows et al (2007) and were sequenced directly in both the forward and reverse direction using Big Dye Terminator v3.1 chemistry (Applied Biosystems, Foster City, CA, USA).…”

“…HA and HB are the most frequently identified haplogroups. These variants were first documented by Wood and Phua (1996) and classified by Hiendleder et al (1998), but have since been located in every geographic region where Ovis aries have been sampled.…”

Further evidence for paternal inheritance of mitochondrial DNA in the sheep (Ovis aries)

“…The complete mtDNA sequence has been determined in sheep (Hiendleder et al, 1998). The displacement loop region (D-loop) is the noncoding control region of the mtDNA, and plays an important role in replication and transcription.…”