Genetic variation in P-glycoprotein in Haemonchus contortus following ivermectin selection

• Main Author: Wang, Guanhua, 1970-
• Other Authors: Prichard, Roger (advisor)
• Format: Others
• Language: en
• Published: McGill University 2002
• Subjects: P-glycoprotein.; Haemonchus contortus.; Ivermectin.; Drug resistance.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79203

Resistance to ivermectin (IVM) in Haemonchus contortus has developed in many countries and its mechanism is still under investigation. P-glycoproteins (P-gp) are transmembrane proteins that can transport drugs out of cells. Researchers have found that there is polymorphism in a P-gp gene from H. contortus between IVM-selected and unselected worms. Three main P-gp polymorphs were identified, polymorph A was found to be related to IVM selection, while polymorphs B and X were associated with susceptibility. The purpose of this research is to investigate the genetic variations in P-glycoprotein that are associated with IVM selection or susceptibility in H. contortus. Total RNA and genomic DNA were extracted from individual male adult worms of IVM-selected and unselected strains of H. contortus. A fragment of the P-gp gene was amplified from the genomic DNA of individual worms and RFLP analysis was performed on the PCR product to genotype the corresponding worms. The homozygous worms that possessed polymorph A, B or X were identified.