Reverse transcription of trypanosome variable antigen mRNAs initiated by a specific oligonucleotide primer.
African trypanosomes change their antigenicity by successively expressing different members of a group of related but highly diverse proteins, the variant surface glycoproteins (VSGs). We describe a synthetic oligonucleotide that can prime specifically reverse transcription of VSG mRNA out of total trypanosome poly(A)+ RNA. The specificity of this priming was verified by cDNA sequence analysis of the transcription products and by the demonstration of variant-specific hybridization of the individual cDNAs to cellular RNA. The oligonucleotide primer also was used as a probe for the conserved sequence found on these VSG mRNAs in trypanosome genomic DNA libraries. A large number of primer-positive clones were detected in a Trypanosoma gambiense genomic library, but very few positive signals were found in a library of Trypanosoma congolense genomic DNA.
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D004247:DNA / Q000235:genetics; D009693:Nucleic Acid Hybridization; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger / Q000235:genetics*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D014346:Trypanosoma brucei brucei / Q000235:genetics*
D000954:Antigens, Surface; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D004247:DNA; D012194:RNA-Directed DNA Polymerase