A model for bacterial conjugal gene transfer on solid surfaces
A model for bacterial conjugal gene transfer on solid surfaces
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DOI：
10.1016/s0168-6496(02)00453-1
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发表时间：
2003-05-01
影响因子：
4.2
通讯作者：
Prosser, JI
中科院分区：
文献类型：
--
作者：
Lagido, C;Wilson, IJ;Prosser, JI
细菌接合的定量模型是环境风险评估和细菌群落生态学和进化研究的有用工具。我们构建了生长在固体表面上的细菌之间基因转移的数学模型。该模型认为供体和受体细胞将形成单独的集落，这些集落呈指数增长，直到营养耗尽。当供体和受体集落相遇时，接合发生，所有受体细胞立即成为transconjugants，之后它们作为供体。通过计算机模拟对该模型进行了理论测试，该计算机模拟遵循单个细菌菌落的历史，并对60%或更低的初始表面覆盖率进行了验证，其中不会发生融合生长。最终数量的供体，受体和transconjugants的模型预测进行了实验测试，使用过滤器交配系统与两个同基因菌株的荧光假单胞菌MON 787作为供体和受体的质粒RP 4。该模型很好地描述了由不同供体和受体接种物、数量和供体：受体比率引起的实验趋势，尽管它经常高估接合0.5-2个数量级。预测大大改善，一般在半个对数单位的实验值，考虑共轭转移的时间。该模型展示了细胞的空间分离和营养有效性之间的关系的transconjugants的数量。该模型为研究表面结合提供了一种机理途径，有助于自然环境中基因转移的研究。(C)2002年由Elsevier Science B. V.代表欧洲微生物学会联合会出版。
Quantitative models of bacterial conjugation are useful tools in environmental risk assessment and in studies of the ecology and evolution of bacterial communities. We constructed a mathematical model for gene transfer between bacteria growing on a solid surface. The model considers that donor and recipient cells will form separate colonies, which grow exponentially until nutrient exhaustion. Conjugation occurs when donor and recipient colonies meet, all recipient cells becoming transconjugants instantly, after which they act as donors. The model was tested theoretically by computer simulations that followed the histories of individual bacterial colonies and was validated for initial surface coverage of 60% or less, where confluent growth does not occur. Model predictions of final number of donors, recipients and transconjugants were tested experimentally using a filter mating system with two isogenic strains of Pseudomonas fluorescens MON787 acting as donor and recipient of plasmid RP4. Experimental trends resulting from varying donor and recipient inoculum, numbers and donor:recipient ratios were well described by the model, although it often overestimated conjugation by 0.5-2 orders of magnitude. Predictions were greatly improved, generally to within half a log unit of experimental values, by consideration of the time for conjugative transfer. The model demonstrates the relationship between spatial separation of cells and nutrient availability on numbers of transconjugants. By providing a mechanistic approach to the study conjugation on surfaces, the model may contribute to the study of gene transfer in natural environments. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.