库拉穆图的一只黑猩猩。
Matthew Berriman及同事通过首次对与“镰刀形疟原虫”密切相关的黑猩猩寄生虫P. reichenowi 的基因组进行完全测序,研究了“镰刀形疟原虫”对人类寄主的适应性的基因组基础。
作者发现,这两个物种的基因组都几乎完全保留了下来,但在与寄生虫生命周期的血液阶段相关的基因上有显著差别。具体来说,他们在寄主-寄生虫界面上发现了变化,这些变化既发生在入侵红血球的过程中,也发生在使被感染细胞表面上的受体产生改变的过程中,它们使其能够附着到寄主内皮细胞上。
另外,他们还发现了少量功能未知的基因,这些基因可能对寄主特异性也有贡献。还需要进一步的研究来确定这些基因中每一个对物种形成和寄主适应的相对贡献。
原文摘要:
Genome sequencing of chimpanzee malaria parasites reveals possible pathways of adaptation to human hosts
Thomas D. Otto, Julian C. Rayner, Ulrike Böhme, Arnab Pain, Natasha Spottiswoode, Mandy Sanders, Michael Quail, Benjamin Ollomo, François Renaud, Alan W. Thomas, Franck Prugnolle, David J. Conway, Chris Newbold & Matthew Berriman
Plasmodium falciparum causes most human malaria deaths, having prehistorically evolved from parasites of African Great Apes. Here we explore the genomic basis of P. falciparum adaptation to human hosts by fully sequencing the genome of the closely related chimpanzee parasite species P. reichenowi, and obtaining partial sequence data from a more distantly related chimpanzee parasite (P. gaboni). The close relationship between P. reichenowi and P. falciparum is emphasized by almost complete conservation of genomic synteny, but against this strikingly conserved background we observe major differences at loci involved in erythrocyte invasion. The organization of most virulence-associated multigene families, including the hypervariable var genes, is broadly conserved, but P. falciparum has a smaller subset of rif and stevor genes whose products are expressed on the infected erythrocyte surface. Genome-wide analysis identifies other loci under recent positive selection, but a limited number of changes at the host–parasite interface may have mediated host switching.
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