Regulation of the rate of asexual growth and commitment to sexual development by diffusible factors from in vitro cultures of Plasmodium falciparum
Regulation of the rate of asexual growth and commitment to sexual development by diffusible factors from in vitro cultures of Plasmodium falciparum
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DOI：
10.4269/ajtmh.2003.68.403
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发表时间：
2003-04-01
影响因子：
3.3
通讯作者：
Day, KP
中科院分区：
文献类型：
--
作者：
Dyer, M;Day, KP
恶性疟原虫的性分化（配子体发生）的切换机制似乎是由对环境条件敏感的随机机制控制的。在任何特定条件下，只有一部分基因相同的寄生虫会致力于性发育。我们使用了一个实验性的共培养系统，以检测存在的扩散分子从无性复制的血液阶段的恶性疟原虫，能够影响寄生虫的生长和分化。我们在一个共享的环境中培养了两个群体的恶性疟原虫，该环境被一个允许分子自由扩散的膜隔开。所呈现的数据表明，培养物中的恶性疟原虫寄生虫刺激其自身的生长和复制，并通过可扩散分子组成性地抑制性转换。这些观察结果支持了恶性疟原虫的模型，即发育的性途径是默认的，并且性途径的组成性抑制允许在人类宿主的血流中发生无性繁殖。
The mechanism of switching to sexual differentiation (gametocytogenesis) of Plasmodium falciparum appears to be controlled by stochastic mechanisms that are sensitive to environmental conditions. In any given conditions, only a proportion of genetically identical parasites will become committed to sexual development. We used an experimental co-culture system to detect the presence of diffusible molecules from asexually replicating bloodstream stages of P. falciparum that were capable of influencing the growth and differentiation of the parasite. We cultured two populations of P. falciparum in a shared environment separated by a membrane that allowed free diffusion of molecules. The data presented show that P. falciparum parasites in culture stimulate their own growth and replication, and constitutively inhibit sexual conversion via diffusible molecules. These observations support the model that for P. falciparum, the sexual pathway of development is the default, and that constitutive repression of the sexual pathway permits asexual multiplication to occur in the bloodstream of the human host.