Optimal foraging by bacteriophages through host avoidance
Optimal foraging by bacteriophages through host avoidance
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DOI：
10.1086/528962
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发表时间：
2008-04-01
影响因子：
2.9
通讯作者：
Bull, James J.
中科院分区：
文献类型：
--
作者：
Heineman, Richard H.;Springman, Rachael;Bull, James J.
最优觅食理论将饮食限制解释为一种适应，以最好地利用一系列质量不同的食物，最差的食物不值得失去寻找更好食物的机会。虽然最佳觅食传统上被应用于动物行为，该模型很容易应用于病毒的宿主范围，这是遗传决定的。对于噬菌体（细菌病毒）的通常观点是，如果不损害对前宿主的适应性，那么扩大宿主范围总是有利的。然而，觅食理论确定的条件有利于避免穷人的主机，即使较大的主机范围没有内在成本。噬菌体T7迅速进化，当一种宿主菌株被改造为杀死感染性大肠杆菌，而另一种仍保持生产力时，它可以区分不同的大肠杆菌菌株。修改细菌产生更微妙的健身效果T7后，我们测试了定性预测的最佳觅食理论的竞争广泛和狭窄的主机范围内相互竞争。与觅食模型一致，当良好的宿主很常见或宿主质量差异很大时，饮食限制是有利的。与该模型相反，选择的方向受到贫穷宿主密度的影响，因为能够区分是昂贵的。
Optimal foraging theory explains diet restriction as an adaptation to best utilize an array of foods differing in quality, the poorest items not worth the lost opportunity of finding better ones. Although optimal foraging has traditionally been applied to animal behavior, the model is easily applied to viral host range, which is genetically determined. The usual perspective for bacteriophages ( bacterial viruses) is that expanding host range is always advantageous if fitness on former hosts is not compromised. However, foraging theory identifies conditions favoring avoidance of poor hosts even if larger host ranges have no intrinsic costs. Bacteriophage T7 rapidly evolved to discriminate among different Escherichia coli strains when one host strain was engineered to kill infecting phages but the other remained productive. After modifying bacteria to yield more subtle fitness effects on T7, we tested qualitative predictions of optimal foraging theory by competing broad and narrow host range phages against each other. Consistent with the foraging model, diet restriction was favored when good hosts were common or there was a large difference in host quality. Contrary to the model, the direction of selection was affected by the density of poor hosts because being able to discriminate was costly.