Alterations in cytochrome-c oxidase expression between praziquantel-resistant and susceptible strains of Schistosoma mansoni.
The genetic differences between praziquantel-resistant (R) and susceptible (S) strains of Schistosoma mansoni (Fallon & Doenhoff, 1994) were explored using RAPD and by cloning differentially expressed mRNAs by subtractive PCR. No differences between the 2 strains were detectable by RAPD using 41 different primers indicating that no major genomic rearrangements were present. Subtractive PCR generated a number of fragments, 1 of which was shown to correspond to an over-expressed mRNA in the R strain and to encode a fragment of the subunit 1 of cytochrome-c oxidase (SCOX1). In the absence of a complete sequence for this gene, we used EST sequences to compile a consensus sequence for the 904 bp at the 3' end that enabled us to choose primers for semi-quantitative RT-PCR. This technique showed that SCOX1 was indeed over-expressed about 5 to 10-fold in the R strain whereas the genes encoding the 28 kDa glutathione S-transferase, glutathione peroxidase, NADH dehydrogenase subunit 5 and the ATP-binding cassette family protein SMDR2 were not. In contrast, cytochrome-c oxidase enzyme activity was 4-fold lower in the R strain than in the S strain.
Pereira
C
C
INSERM U167 'Relations hôte-parasite et stratégies vaccinales', Institut Pasteur de Lille, France.
Fallon
P G
PG
Cornette
J
J
Capron
A
A
Doenhoff
M J
MJ
Pierce
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D000980:Antiplatyhelmintic Agents / Q000494:pharmacology*; D001483:Base Sequence; D001700:Biomphalaria; D015152:Blotting, Northern; D016384:Consensus Sequence; D006224:Cricetinae; D017931:DNA Primers; D004351:Drug Resistance / Q000235:genetics; D003576:Electron Transport Complex IV / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D007630:Kenya; D008647:Mesocricetus; D051379:Mice; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D011223:Praziquantel / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D019105:Random Amplified Polymorphic DNA Technique; D012550:Schistosoma mansoni / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D012675:Senegal; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D000980:Antiplatyhelmintic Agents; D017931:DNA Primers; D012333:RNA, Messenger; D011223:Praziquantel; D003576:Electron Transport Complex IV