Department of Biology, York Biomedical Research Institute, University of York, York, United Kingdom.
Instituto de Doenças do Sertão, Instituto de Doenças Tropicais Natan Portella, Centro de Ciências da Saúde da Universidade Federal do Piauí, Teresina-PI, Brazil.
Genome Biol Evol. 2021 Dec 1;13(12). doi: 10.1093/gbe/evab265.
The Leishmania donovani species complex is the causative agent of visceral leishmaniasis, which cause 20-40,000 fatalities a year. Here, we conduct a screen for balancing selection in this species complex. We used 384 publicly available L. donovani and L. infantum genomes, and sequence 93 isolates of L. infantum from Brazil to describe the global diversity of this species complex. We identify five genetically distinct populations that are sufficiently represented by genomic data to search for signatures of selection. We find that signals of balancing selection are generally not shared between populations, consistent with transient adaptive events, rather than long-term balancing selection. We then apply multiple diversity metrics to identify candidate genes with robust signatures of balancing selection, identifying a curated set of 24 genes with robust signatures. These include zeta toxin, nodulin-like, and flagellum attachment proteins. This study highlights the extent of genetic divergence between L. donovani complex parasites and provides genes for further study.
杜氏利什曼原虫种复合体是内脏利什曼病的病原体，每年导致 2 万至 4 万人死亡。在这里，我们对该种复合体中的平衡选择进行了筛选。我们使用了 384 个公开的杜氏利什曼原虫和婴儿利什曼原虫基因组，并对来自巴西的 93 株婴儿利什曼原虫进行了测序，以描述该种复合体的全球多样性。我们确定了五个在基因组数据中得到充分代表的遗传上不同的群体，以搜索选择的迹象。我们发现，平衡选择的信号在群体之间通常没有共享，这与短暂的适应性事件一致，而不是长期的平衡选择。然后，我们应用多种多样性指标来识别具有稳健平衡选择信号的候选基因，确定了一组 24 个具有稳健平衡选择信号的基因。这些基因包括 Zeta 毒素、类结节素和鞭毛附着蛋白。本研究强调了杜氏利什曼原虫复合体寄生虫之间遗传分化的程度，并提供了进一步研究的基因。
