Laboratorio de Malaria, Centro de Pesquisas René Rachou/Fiocruz, Belo Horizonte, Brazil.
Trop Med Int Health. 2010 Jun;15(6):718-26. doi: 10.1111/j.1365-3156.2010.02535.x. Epub 2010 Apr 6.
To describe the genetic diversity of Plasmodium vivax isolates from different areas in the Brazilian Amazon using 11 polymorphic microsatellites and to evaluate the correlation between microsatellite variation and repeat array length.
Microsatellites with variable repeat units and array lengths were selected using in silico search of the P. vivax genome. We designed primers and amplified the selected loci in DNA obtained from patients with P. vivax acute infections.
Positive correlation between repeat array length and microsatellite variation was detected independently of the size of repeat unit (di, tri, or tetranucleotide). We used these markers to describe the genetic variability of P. vivax isolates from four geographic regions of the Brazilian Amazon. Substantial variability was observed among P. vivax isolates within populations, concurrent with high levels of multiple-clone infections and high linkage disequilibrium. Overall, structured populations were observed with moderate to high genetic differentiation.
The markers studied are useful tools for assessing population structure of P. vivax, as demonstrated for Brazilian populations and for searching for evidence of recent selection events associated with different phenotypes, such as drug resistance.
利用 11 个多态性微卫星标记描述巴西亚马逊地区不同地区间间日疟原虫分离株的遗传多样性，并评估微卫星变异与重复序列长度之间的相关性。
通过对间日疟原虫基因组的计算机搜索，选择具有可变重复单元和重复序列长度的微卫星。我们设计了引物，并在来自间日疟原虫急性感染患者的 DNA 中扩增了所选基因座。
在不考虑重复单元（二核苷酸、三核苷酸或四核苷酸）大小的情况下，检测到重复序列长度与微卫星变异之间的正相关。我们使用这些标记物来描述巴西亚马逊地区四个地理区域间日疟原虫分离株的遗传变异性。在种群内观察到大量的间日疟原虫分离株变异，同时存在高水平的多克隆感染和高度的连锁不平衡。总体而言，观察到具有中度至高度遗传分化的结构种群。
研究中使用的标记物是评估间日疟原虫种群结构的有用工具，这在巴西种群中得到了证明，并可用于寻找与不同表型（如耐药性）相关的近期选择事件的证据。
