Finley R W, Dvorak J A
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
J Protozool. 1987 Nov;34(4):409-15. doi: 10.1111/j.1550-7408.1987.tb03202.x.
Utilizing the previously reported inter-clonal differences in total DNA/organism, flow cytometry was used to analyze the population dynamics of Trypanosoma cruzi clone mixtures growing in liquid medium or vertebrate cells. The growth of clone mixtures in liquid medium can be described by unique parameters reflecting exponential growth rate (r), stationary phase population density (1/k), and the interaction between the clones (h). The relative numbers of each clone in the population change rapidly with time and the results are in quantitative agreement with mathematical models of competitive population growth. The relationship between the parameters for T. cruzi is such that, in general, there is no dynamic equilibrium with coexistence of clones with different growth rates; under all culture protocols, the faster growing clone will prevail. A computer simulation of the vertebrate cell cycle of T. cruzi suggests that clone mixtures grow relatively independently; the basic attributes of the model were substantiated experimentally. Although wide fluctuations in the proportion of each clone released occurred, the faster growing clone again predominated. Finally, these results underline the importance of working with well-defined clones in the laboratory to avoid inconsistencies and paradoxical results and stress the importance of the rapid isolation of single cell clones from clinical specimens when studying the relationship of the parasite to human disease.
利用先前报道的不同克隆间总DNA/生物体的差异，采用流式细胞术分析了克氏锥虫克隆混合物在液体培养基或脊椎动物细胞中生长时的群体动态。克隆混合物在液体培养基中的生长可用反映指数生长速率（r）、稳定期群体密度（1/k）以及克隆间相互作用（h）的独特参数来描述。群体中各克隆的相对数量随时间迅速变化，结果与竞争群体生长的数学模型在数量上一致。克氏锥虫参数之间的关系表明，一般来说，不同生长速率的克隆共存时不存在动态平衡；在所有培养方案下，生长较快的克隆将占主导。对克氏锥虫脊椎动物细胞周期的计算机模拟表明，克隆混合物相对独立生长；该模型的基本特性通过实验得到了证实。尽管释放的各克隆比例存在广泛波动，但生长较快的克隆再次占主导。最后，这些结果强调了在实验室中使用明确界定的克隆进行研究以避免不一致和矛盾结果的重要性，并强调了在研究寄生虫与人类疾病关系时从临床标本中快速分离单细胞克隆的重要性。
