The malaria parasite, Plasmodium falciparum, was introduced into Hispaniola and other regions of the Americas through the slave trade spanning the 16th through the 19th centuries. During this period, more than 12 million Africans were brought across the Atlantic to the Caribbean and other regions of the Americas. Since malaria is holoendemic in West Africa, a substantial percentage of these individuals carried the parasite. St. Domingue on Hispaniola, now modern-day Haiti, was a major port of disembarkation, and malaria is still actively transmitted there. We undertook a detailed study of the phylogenetics of the Haitian parasites and those from Colombia and Peru utilizing whole-genome sequencing. Principal-component and phylogenetic analyses, based upon single nucleotide polymorphisms (SNPs) in protein coding regions, indicate that, despite the potential for millions of introductions from Africa, the Haitian parasites share an ancestral relationship within a well-supported monophyletic clade with parasites from South America, while belonging to a distinct lineage. This result, in stark contrast to the historical record of parasite introductions, is best explained by a severe population bottleneck experienced by the parasites introduced into the Americas. Here, evidence is presented for targeted selection of rare African alleles in genes which are expressed in the mosquito stages of the parasite’s life cycle. These genetic markers support the hypothesis that the severe population bottleneck was caused by the required adaptation of the parasite to transmission by new definitive hosts among the Anopheles (Nyssorhynchus) spp. found in the Caribbean and South America.

中文翻译：

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海地和南美洲寄生虫基因组中发现的恶性疟原虫适应美国载体传播的遗传标记

疟原虫恶性疟原虫通过 16 世纪至 19 世纪的奴隶贸易被引入伊斯帕尼奥拉岛和美洲其他地区。在此期间，超过1200万非洲人被带到大西洋彼岸，到达加勒比海和美洲其他地区。由于疟疾在西非是大流行病，因此这些人中很大一部分人携带这种寄生虫。伊斯帕尼奥拉岛的圣多明各（现在的海地）是一个主要的登陆港，疟疾仍然在那里活跃传播。我们利用全基因组测序对海地寄生虫以及哥伦比亚和秘鲁寄生虫的系统发育进行了详细研究。基于蛋白质编码区单核苷酸多态性 (SNP) 的主成分和系统发育分析表明，尽管有可能从非洲引进数百万种海地寄生虫，但海地寄生虫在一个得到充分支持的单系进化支中与来自非洲的寄生虫有着共同的祖先关系。南美洲，虽然属于一个独特的血统。这一结果与寄生虫引入的历史记录形成鲜明对比，最好的解释是引入美洲的寄生虫所经历的严重的种群瓶颈。在这里，提出了有针对性地选择在寄生虫生命周期的蚊子阶段表达的基因中稀有非洲等位基因的证据。这些遗传标记支持这样的假设，即严重的种群瓶颈是由于寄生虫需要适应按蚊（ Nyssorhynchus ）中新的最终宿主的传播而造成的。发现于加勒比海和南美洲。