Holland Jacob G, O'Donnell Aidan J, Herbert-Mainero Alejandra, Reece Sarah E
Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK.
Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
Philos Trans R Soc Lond B Biol Sci. 2025 Jan 23;380(1918):20230340. doi: 10.1098/rstb.2023.0340.
The environments that parasites experience within hosts change dramatically over 24 h. How rhythms shape host-parasite-vector interactions is poorly understood owing to the challenges of disentangling the roles of rhythms of multiple interacting species in the context of the complex lifecycles of parasites. Using canonical circadian clock-disrupted hosts, we probe the limits of flexibility in the rhythmic replication of malaria () parasites and quantify the consequences for fitness proxies of both parasite and host. We reveal that parasites alter the duration of their replication rhythm to resonate with host rhythms that have short (21 h) daily T-cycles as accurately as when infecting hosts with 24 h cycles, but appear less capable of extending their replication rhythm in hosts with long (27 h) cycles. Despite matching the period of short T-cycle hosts, parasites are unable to lock to the correct phase, likely leading to lower within-host productivity and a reduction in transmission potential. However, parasites in long T-cycle hosts do not experience substantial fitness costs. Furthermore, T-cycle duration does not affect disease severity in clock-disrupted hosts. Understanding the rhythmic replication of malaria parasites offers the opportunity to interfere with parasite timing to improve health and reduce transmission.This article is part of the Theo Murphy meeting issue issue 'Circadian rhythms in infection and immunity'.
寄生虫在宿主体内所经历的环境在24小时内会发生巨大变化。由于在寄生虫复杂的生命周期背景下，难以厘清多个相互作用物种的节律作用，因此对于节律如何塑造宿主 - 寄生虫 - 媒介相互作用的了解甚少。我们使用典型的生物钟紊乱宿主，探究疟原虫节律性复制的灵活性极限，并量化对寄生虫和宿主适应性指标的影响。我们发现，寄生虫会改变其复制节律的时长，以便与每日T周期较短（21小时）的宿主节律同步，其精确程度与感染T周期为24小时的宿主时相同，但在T周期较长（27小时）的宿主中，寄生虫似乎不太能够延长其复制节律。尽管与短T周期宿主的周期相匹配，但寄生虫无法锁定到正确的相位，这可能导致宿主体内的繁殖力降低以及传播潜力下降。然而，长T周期宿主中的寄生虫并未经历显著的适应性代价。此外，T周期时长并不影响生物钟紊乱宿主的疾病严重程度。了解疟原虫的节律性复制为干预寄生虫的时间节律以改善健康状况和减少传播提供了机会。本文是西奥·墨菲会议议题“感染与免疫中的昼夜节律”的一部分。
