Importance of the mutation of amino acid 200 of the isotype 1 beta-tubulin gene in the benzimidazole resistance of the small-ruminant parasite Teladorsagia circumcincta

Parasitol Res. 1999 Jun;85(6):452-6. doi: 10.1007/s004360050577.

Abstract

In this work we demonstrated that the acquisition of benzimidazole (BZ) resistance in the small-ruminant parasite Teladorsagia circumcincta is linked to the selection of individuals that are characterized by a tyrosine (Tyr) at amino acid 200 of their isotype 1 beta-tubulin gene. This mutation appears to be recessive, since only homozygous mutant (Tyr/Tyr) individuals survived after BZ treatment of two resistant populations in which the three genotypes (rr, rs, ss) were initially present. In comparison with natural BZ-susceptible populations, a decrease in the restriction polymorphism (RFLP) of the isotype 1 beta-tubulin gene was observed in natural resistant populations. It seems that this decrease in beta-tubulin polymorphism results from the selection of homozygous mutant individuals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzimidazoles / pharmacology*
  • Drug Resistance
  • Genes, Recessive
  • Goats
  • Homozygote
  • Mutation*
  • Ostertagia / drug effects*
  • Polymorphism, Restriction Fragment Length
  • Protein Isoforms / genetics
  • Ruminants / parasitology*
  • Selection, Genetic
  • Sheep
  • Tubulin / genetics*

Substances

  • Benzimidazoles
  • Protein Isoforms
  • Tubulin
  • benzimidazole