Volume 74, Issue 4
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


We determined the nucleotide sequence of the cytochrome b () gene. DNA was extracted from isolated from Aomori Prefecture, Japan, and 1,288 basepairs of the gene, including 1,071 basepairs of the open reading frame, were sequenced. The gene of obtained from three dogs that had been experimentally infected with and treated with atovaquone was also sequenced. The gene obtained from all three atovaquone-treated dogs contained a single polymorphism resulting in an amino acid change in one of the putative ubiquinone-binding sites of . This polymorphism was homologous to mutations in other apicomplexan protozoa that exhibit resistance to atovaquone. Two other single polymorphisms were identified in parasites isolated from two of the dogs. These results indicate that single nucleotide polymorphisms in the sequence for mitochondrial gene may be associated with decreased susceptibility of species to atovaquone.


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  • Received : 27 Jun 2005
  • Accepted : 13 Sep 2005

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