Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA 02115, USA.
Cell. 2019 Apr 4;177(2):315-325.e14. doi: 10.1016/j.cell.2019.02.036. Epub 2019 Mar 28.
Transmission of malaria parasites occurs when a female Anopheles mosquito feeds on an infected host to acquire nutrients for egg development. How parasites are affected by oogenetic processes, principally orchestrated by the steroid hormone 20-hydroxyecdysone (20E), remains largely unknown. Here we show that Plasmodium falciparum development is intimately but not competitively linked to processes shaping Anopheles gambiae reproduction. We unveil a 20E-mediated positive correlation between egg and oocyst numbers; impairing oogenesis by multiple 20E manipulations decreases parasite intensities. These manipulations, however, accelerate Plasmodium growth rates, allowing sporozoites to become infectious sooner. Parasites exploit mosquito lipids for faster growth, but they do so without further affecting egg development. These results suggest that P. falciparum has adopted a non-competitive evolutionary strategy of resource exploitation to optimize transmission while minimizing fitness costs to its mosquito vector. Our findings have profound implications for currently proposed control strategies aimed at suppressing mosquito populations.
疟原虫的传播发生在雌性疟蚊吸食受感染的宿主以获取卵发育所需的营养时。然而，寄生虫是如何受到卵发生过程的影响的，主要是由类固醇激素 20-羟基蜕皮醇（20E）调控的，在很大程度上仍然未知。在这里，我们表明恶性疟原虫的发育与塑造冈比亚按蚊繁殖的过程密切相关，但不是竞争关系。我们揭示了 20E 介导的卵和卵囊数量之间的正相关；通过多种 20E 操作破坏卵子发生会降低寄生虫的强度。然而，这些操作会加速疟原虫的生长速度，使孢子能够更早地具有感染性。寄生虫利用蚊子的脂质来实现更快的生长，但不会进一步影响卵的发育。这些结果表明，恶性疟原虫已经采取了一种非竞争的资源利用进化策略，以优化传播，同时将对其蚊子媒介的适应度成本降到最低。我们的发现对目前提出的旨在抑制蚊子种群的控制策略具有深远的意义。
