Schousboe Mette L, Ranjitkar Samir, Rajakaruna Rupika S, Amerasinghe Priyanie H, Konradsen Flemming, Morales Francisco, Ord Rosalynn, Pearce Richard, Leslie Toby, Rowland Mark, Gadalla Nahla, Bygbjerg Ib C, Alifrangis Michael, Roper Cally
Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1 4HT, UK.
Malar J. 2014 Oct 2;13:392. doi: 10.1186/1475-2875-13-392.
Even though Plasmodium vivax has the widest worldwide distribution of the human malaria species and imposes a serious impact on global public health, the investigation of genetic diversity in this species has been limited in comparison to Plasmodium falciparum. Markers of genetic diversity are vital to the evaluation of drug and vaccine efficacy, tracking of P. vivax outbreaks, and assessing geographical differentiation between parasite populations.
The genetic diversity of eight P. vivax populations (n=543) was investigated by using two microsatellites (MS), m1501 and m3502, chosen because of their seven and eight base-pair (bp) repeat lengths, respectively. These were compared with published data of the same loci from six other P. vivax populations.
In total, 1,440 P. vivax samples from 14 countries on three continents were compared. There was highest heterozygosity within Asian populations, where expected heterozygosity (He) was 0.92-0.98, and alleles with a high repeat number were more common. Pairwise FST revealed significant differentiation between most P. vivax populations, with the highest divergence found between Asian and South American populations, yet the majority of the diversity (~89%) was found to exist within rather than between populations.
The MS markers used were informative in both global and local P. vivax population comparisons and their seven and eight bp repeat length facilitated population comparison using data from independent studies. A complex spatial pattern of MS polymorphisms among global P. vivax populations was observed which has potential utility in future epidemiological studies of the P. vivax parasite.
尽管间日疟原虫是在全球分布最广泛的人类疟原虫物种，对全球公共卫生造成了严重影响，但与恶性疟原虫相比，对该物种遗传多样性的研究一直较为有限。遗传多样性标记对于评估药物和疫苗疗效、追踪间日疟原虫疫情以及评估寄生虫种群之间的地理分化至关重要。
通过使用两个微卫星（MS），即m1501和m3502，对8个间日疟原虫种群（n = 543）的遗传多样性进行了研究，选择这两个微卫星是因为它们的重复长度分别为7个和8个碱基对（bp）。将这些结果与来自其他6个间日疟原虫种群相同位点的已发表数据进行了比较。
总共比较了来自三大洲14个国家的1440份间日疟原虫样本。亚洲种群内的杂合度最高，预期杂合度（He）为0.92 - 0.98，且具有高重复数的等位基因更为常见。成对FST显示大多数间日疟原虫种群之间存在显著分化，亚洲和南美洲种群之间的差异最大，但发现大多数多样性（约89%）存在于种群内部而非种群之间。
所使用的微卫星标记在全球和本地间日疟原虫种群比较中均具有信息价值，其7个和8个bp的重复长度便于利用独立研究的数据进行种群比较。观察到全球间日疟原虫种群中微卫星多态性的复杂空间模式，这在未来间日疟原虫寄生虫的流行病学研究中具有潜在用途。
