Possible DNA modification in GC dinucleotides of Trypanosoma brucei telomeric sequences; relationship with antigen gene transcription

Nucleic Acids Res. 1984 Jul 11;12(13):5235-47. doi: 10.1093/nar/12.13.5235.


Polymorphism in restriction site cleavage (PstI, SphI, PvuII, HindIII) has been noticed in several occasions in the telomeric sequences harbouring trypanosome variant-specific antigen genes (1, 2, 3). This polymorphism has been further investigated and seems best interpreted as due to partial DNA modification in GC dinucleotides. The actively transcribed telomeric genes do not exhibit such a polymorphism; furthermore, in at least three independent cases, gene inactivation is linked to the appearance of polymorphism. It could thus be hypothesized that DNA modification prevents antigen gene transcription, or vice-versa. We report however that at least some telomeric antigen-specific sequences of the procyclic trypanosomes (in vitro culture form) are not polymorphic, although they do not synthesize any variant-specific antigen mRNA. There is thus no absolute relationship between the absence of polymorphism and antigen gene transcription.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA / genetics*
  • DNA Restriction Enzymes
  • Genes*
  • Glycoproteins / genetics*
  • Oligodeoxyribonucleotides / analysis*
  • Oligonucleotides / analysis*
  • Polymorphism, Genetic
  • RNA, Messenger / genetics
  • Transcription, Genetic*
  • Trypanosoma brucei brucei / genetics*
  • Variant Surface Glycoproteins, Trypanosoma


  • Glycoproteins
  • Oligodeoxyribonucleotides
  • Oligonucleotides
  • RNA, Messenger
  • Variant Surface Glycoproteins, Trypanosoma
  • DNA
  • DNA Restriction Enzymes