title: Extensive heterozygosity in flanking microsatellites of Plasmodium falciparum Na+/H+ exchanger (pfnhe-1) gene among Indian isolates.
abstract: Plasmodium falciparum Na(+)/H(+) exchanger-1 (pfnhe-1) gene has been proposed to be a possible marker for quinine resistance. Here, we describe the sequence analysis of the flanking microsatellites of the pfnhe-1 gene among 108 Indian P.falciparum isolates. Among the parasite population, a high degree of polymorphism was observed at all the 10 microsatellite loci within +/-40kb region of the pfnhe-1 gene where the number of alleles varied from 2 to 16 with a high expected heterozygosity ranging from 0.43 to 0.91 at these loci. Also, higher levels of heterozygosity have been observed in P.falciparum isolates collected from both low and high transmission and drug resistant areas. Furthermore, there was no association between QN resistance associated DNNND repeats in PFNHE-1 and the flanking microsatellite haplotypes. In conclusion, the observed high level of microsatellite polymorphism and absence of selective sweep in the flanking +/-40kb region of the pfnhe-1 gene could be an indication that there is no strong selection pressure on this target gene.
authors.affiliation: Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Vandana
authors.initials: V
authors.lastname: Choudhary
authors.forename: Yagya D
authors.initials: YD
authors.lastname: Sharma
mesh_terms: D024509:3' Flanking Region; D024506:5' Flanking Region; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D016172:DNA Fingerprinting; D016054:DNA, Protozoan / Q000235:genetics; D004351:Drug Resistance; D006579:Heterozygote; D007194:India; D016778:Malaria, Falciparum / Q000469:parasitology*; D018895:Microsatellite Repeats; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D011803:Quinine / Q000494:pharmacology; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics*
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D017923:Sodium-Hydrogen Exchangers; D011803:Quinine