Information use and plasticity in the reproductive decisions of malaria parasites.
Information use and plasticity in the reproductive decisions of malaria parasites.
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DOI：
10.1186/1475-2875-13-115
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发表时间：
2014-03-26
期刊：
影响因子：
3
通讯作者：
Reece SE
中科院分区：
文献类型：
--
作者：
Carter LM;Schneider P;Reece SE
投资于产生可传播阶段（配子体）及其性别比例是疟疾寄生虫的特征，是蚊子传染性的基础，因此是流行病学的核心。疟疾寄生虫根据宿主内环境的变化（包括红细胞资源可用性、宿主免疫反应、混合感染中来自同特异性基因型的竞争以及药物治疗）调整其对配子体的投资水平和性别比例。这种可塑性似乎是适应性的（战略性的），因为寄生虫优先考虑投资（在有性阶段与无性阶段，雄性阶段与雌性阶段），以最大限度地提高适应性。然而，寄生虫用来探测环境变化并对投资配子体及其性别比例做出适当决定的信息或“线索”是未知的。将单基因型沙伯迪疟原虫感染暴露于“线索”处理，包括完整或裂解的未感染红细胞、裂解的同一克隆或无关克隆的寄生红细胞和未经处理的对照。监测感染动态（网状红细胞、红细胞和无性期寄生虫密度的比例），并检查配子细胞投资和性别比例在感染高峰前或高峰后对cue处理的反应。观察到，由于存在裂解的寄生虫物质，配子体密度显著降低，并且在暴露于裂解的红细胞（未感染和感染）后，观察到性别比例（雄性配子体的比例）显着增加。此外，配子细胞密度和性别比例的变化对这些线索的反应取决于感染的年龄。证明在感染过程中观察到的配子体投资和性别比例的变化是寄生虫策略的结果（而不是宿主生理的足迹），为研究可塑性的适应性后果和探索是否可以开发药物来欺骗寄生虫做出次优决策提供了基础。
Investment in the production of transmissible stages (gametocytes) and their sex ratio are malaria parasite traits that underpin mosquito infectivity and are therefore central to epidemiology. Malaria parasites adjust their levels of investment into gametocytes and sex ratio in response to changes in the in-host environment (including red blood cell resource availability, host immune responses, competition from con-specific genotypes in mixed infections, and drug treatment). This plasticity appears to be adaptive (strategic) because parasites prioritize investment (in sexual versus asexual stages and male versus female stages) in manners predicted to maximize fitness. However, the information, or ‘cues’ that parasites use to detect environmental changes and make appropriate decisions about investment into gametocytes and their sex ratio are unknown. Single genotype Plasmodium chabaudi infections were exposed to ‘cue’ treatments consisting of intact or lysed uninfected red blood cells, lysed parasitized RBCs of the same clone or an unrelated clone, and an unmanipulated control. Infection dynamics (proportion of reticulocytes, red blood cell and asexual stage parasite densities) were monitored, and changes in gametocyte investment and sex ratio in response to cue treatments, applied either pre- or post-peak of infection were examined. A significant reduction in gametocyte density was observed in response to the presence of lysed parasite material and a borderline significant increase in sex ratio (proportion of male gametocytes) upon exposure to lysed red blood cells (both uninfected and infected) was observed. Furthermore, the changes in gametocyte density and sex ratio in response to these cues depend on the age of infection. Demonstrating that variation in gametocyte investment and sex ratio observed during infections are a result of parasite strategies (rather than the footprint of host physiology), provides a foundation to investigate the fitness consequences of plasticity and explore whether drugs could be developed to trick parasites into making suboptimal decisions.
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DOI：
10.1182/asheducation-2009.1.87
发表时间：
2009
期刊：
Hematology. American Society of Hematology. Education Program
影响因子：
--
作者：
Haldar K;Mohandas N
通讯作者：
Mohandas N
影响因子：
2.4
作者：
CARTER, R
通讯作者：
CARTER, R
影响因子：
64.8
作者：
通讯作者：
--
DOI：
10.4269/ajtmh.2003.68.403
发表时间：
2003-04-01
影响因子：
3.3
作者：
Dyer, M;Day, KP
通讯作者：
Day, KP
DOI：
10.1016/s0035-9203(98)90913-0
发表时间：
1998-09-01
影响因子：
2.2
作者：
Ekvall, H;Premji, Z;Björkman, A
通讯作者：
Björkman, A