Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia; email:
Annu Rev Microbiol. 2013;67:271-89. doi: 10.1146/annurev-micro-092412-155741. Epub 2013 Jun 26.
Plasmodium and Toxoplasma are genera of apicomplexan parasites that infect millions of people each year. The former causes malaria, and the latter causes neurotropic infections associated with a weakened or developing immune system. These parasites harbor a peculiar organelle, the apicoplast. The apicoplast is the product of an ancient endosymbiosis between a heterotrophic and a photosynthetic protist. We explore the cellular and molecular mechanisms that enabled a stable union of two previously independent organisms. These include the exchange of metabolites, transfer of genes, transport of proteins, and overall coordination of biogenesis and proliferation. These mechanisms are still active today and can be exploited to treat parasite infection. They were shaped by the dramatic changes that occurred in the evolution of the phylum Apicomplexa--including the gain and loss of photosynthesis, adaptation to symbiosis and parasitism, and the explosion of animal diversity-that ultimately provided an aquatic alga access to every biotope on this planet.
疟原虫和刚地弓形虫是顶复门寄生虫的属，每年感染数百万人。前者引起疟疾，后者引起与免疫系统减弱或发育相关的神经感染。这些寄生虫拥有一种特殊的细胞器，即顶质体。顶质体是一种异养生物和光合原生生物之间古老内共生的产物。我们探索了使两个先前独立的生物体稳定结合的细胞和分子机制。这些机制包括代谢物交换、基因转移、蛋白质转运以及生物发生和增殖的整体协调。这些机制至今仍在发挥作用，可以用来治疗寄生虫感染。它们是由顶复门进化过程中发生的剧烈变化塑造的，包括光合作用的获得和丧失、对共生和寄生的适应以及动物多样性的爆发，这最终使水生藻类能够进入这个星球上的每一个生境。
