Mol Biol Evol. 2012 Sep;29(9):2095-9. doi: 10.1093/molbev/mss082. Epub 2012 Mar 6.
Apicoplast, a nonphotosynthetic plastid derived from secondary symbiotic origin, is essential for the survival of malaria parasites of the genus Plasmodium. Elucidation of the evolution of the apicoplast genome in Plasmodium species is important to better understand the functions of the organelle. However, the complete apicoplast genome is available for only the most virulent human malaria parasite, Plasmodium falciparum. Here, we obtained the near-complete apicoplast genome sequences from eight Plasmodium species that infect a wide variety of vertebrate hosts and performed structural and phylogenetic analyses. We found that gene repertoire, gene arrangement, and other structural attributes were highly conserved. Phylogenetic reconstruction using 30 protein-coding genes of the apicoplast genome inferred, for the first time, a close relationship between P. ovale and rodent parasites. This close relatedness was robustly supported using multiple evolutionary assumptions and models. The finding suggests that an ancestral host switch occurred between rodent and human Plasmodium parasites.
类质体，一种来源于二次共生的非光合质体，对于疟原虫属的疟原虫的生存是必不可少的。阐明疟原虫种类中的类质体基因组的进化对于更好地理解细胞器的功能很重要。然而，完整的类质体基因组仅可用于最具毒性的人类疟原虫，即恶性疟原虫。在这里，我们从感染各种脊椎动物宿主的八种疟原虫中获得了近完整的类质体基因组序列，并进行了结构和系统发育分析。我们发现基因库、基因排列和其他结构特征高度保守。使用质体基因组的 30 个蛋白编码基因进行的系统发育重建首次推断出卵形疟原虫与啮齿动物寄生虫之间的密切关系。使用多种进化假设和模型强有力地支持了这种密切关系。这一发现表明，啮齿动物和人类疟原虫寄生虫之间发生了祖先宿主的转换。
