SEQUENCE VARIATION IN THE OVINE CYTOCHROME-B GENE

The complete mitochondrial cytochrome b sequences of two Merinolandsch af individuals, preselected for mtDNA divergence on the basis of RFLP data, were determined and compared with a published sequence of Ovis a ries. A total of 14 variable nucleotide positions were identified, the majority of these were silent third-position transitions. Sequence di fferences ranged from 0.18% to 1.23%. A total of three variable residu es (Ala/Gly, Ile/Val) in the predicted amino-acid sequence was detecte d. The replacements can be considered conservative, and are located in the transmembrane regions of the protein. An influence on electron tr ansport is therefore unlikely, although influences on enzyme function cannot be completely ruled out.