Involvement of mitochondrial genes of Babesia gibsoni in resistance to diminazene aceturate.
The stability of the characteristics of the diminazene aceturate (DA)-resistant B. gibsoni isolate was initially determined in vitro. Part of the DA-resistant B. gibsoni isolate was cultured without DA for 4 weeks, and then newly exposed to 200 ng/ml DA. As a result, this isolate could proliferate the same as the DA-resistant isolate, indicating that the characteristic of DA resistance was stable in the DA-resistant isolate. Additionally, the level of parasitemia in the DA-resistant isolate was comparatively lower than in the wild-type, suggesting that the proliferation potential of the DA-resistant isolate would be lower than that of the wild-type. Subsequently, to investigate the involvement of mitochondrial DNA (mtDNA) in DA resistance in B. gibsoni, the nucleotide sequences and deduced amino acid sequences of mitochondrial genes such as COXI, COXIII, and CYTb genes of the DA-resistant isolate, were compared with those of the wild-type. As a result, these three genes were not altered in the DA-resistant B. gibsoni isolate. Moreover, the transcription levels of COXI, COXIII, and CYTb genes were observed by semi-quantitative RT-PCR. As a result, the gene transcription of those genes in the DA-resistant isolate was not significantly altered. These results indicated that DA did not affect mtDNA directly in DA-resistant B. gibsoni. Thus, it is suggested that mtDNA should not be deeply involved in DA resistance in B. gibsoni.
Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Bandula Kumara
BK
Wickramasekara Rajapakshage
Masahiro
M
Yamasaki
Shiang-Jyi
SJ
Hwang
Noboru
N
Sasaki
Masahiro
M
Murakami
Yu
Y
Tamura
Sue Yee
SY
Lim
Kensuke
K
Nakamura
Hiroshi
H
Ohta
Mitsuyoshi
M
Takiguchi
D000595:Amino Acid Sequence; D000981:Antiprotozoal Agents; D001403:Babesia / Q000235:genetics*; D001483:Base Sequence; D046508:Culture Techniques / Q000379:methods; D017931:DNA Primers / Q000235:genetics; D004133:Diminazene / Q000031:analogs & derivatives; D004351:Drug Resistance / Q000235:genetics*; D050259:Genes, Mitochondrial / Q000235:genetics*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D000981:Antiprotozoal Agents; D017931:DNA Primers; C003915:diminazene aceturate; D004133:Diminazene