Variation of the Chloroquine Resistance Transporter (Crt) Gene in Chloroquine-Resistant and Chloroquine-Sensitive Plasmodium berghei

Background: The emergence and spread of chloroquine resistant Plasmodium falciparum in the world stimulated some investigators to consider different aspects of chloroquine resistance in human and rodent Plasmodia. Using animal Plasmodia, particularly primate and rodent Plasmodia can be useful model for human Plasmodia studies. In this study we have tried to consider and compare the sequence of chloroquine resistance transporter (crt) gene among chloroquine-resistant and chloroquine–sensitive strains of Plasmodium berghei. Methods: This experimental study was performed at the Malaria Laboratory of School of public health. DNA was extracted from two strains of P. berghei which their resistance and sensitivity had been demonstrated in mice with treatment by chloroquine. By using specific primer for crt gene some parts of this gene were amplified by PCR, and obtained fragments were then sequenced and compared. Results: There were considerable differences in crt gene between two strains. Sequenced 1212 bp of crt gene fragment in the two strains showed 43 differences at nucleotides level and 16 differences in presumed coding amino acids. Conclusion: crt can be addressed as a considerable gene which involves in induction of resistance to chloroquine in P. berghei, as P. falciparum. The results increased such a promise that considering crt gene in chloroquine-sensitive and chloroquine-resistant P. berghei can prepare suitable and helpful fields for more understanding the molecular aspects of chloroquine-resistance in Plasmodia and reversing the effectiveness of 4-aminoquinolines particularly chloroquine for treatment of drug resistant Plasmodia.