SELECTION FOR TRYPTOPHAN AUXOTROPHS OF ESCHERICHIA-COLI IN GLUCOSE-LIMITED CHEMOSTATS AS A TEST OF ENERGY-CONSERVATION HYPOTHESIS OF EVOLUTION
SELECTION FOR TRYPTOPHAN AUXOTROPHS OF ESCHERICHIA-COLI IN GLUCOSE-LIMITED CHEMOSTATS AS A TEST OF ENERGY-CONSERVATION HYPOTHESIS OF EVOLUTION
复制标题
DOI：
10.1111/j.1558-5646.1978.tb01103.x
复制
发表时间：
1978-01-01
期刊：
影响因子：
3.3
通讯作者：
DYKHUIZEN, D
中科院分区：
文献类型：
--
作者：
DYKHUIZEN, D
向营养不良的进化可以用效率论来解释，其正式表述为能量守恒假说，即选择的速度取决于通过消除不必要的过程而节省的能量的数量。这一假设通过大肠杆菌色氨酸突变体与等基因野生型大肠杆菌在具有过量色氨酸的葡萄糖限制趋化剂中竞争来验证。突变体的选择比可以节省的能量预算的理论百分比大3个数量级。没有发现人口统计学上的差异来解释这种巨大的选择。在相同环境下的突变体和在不同环境下的相同突变体之间的选择率没有预测的相对差异。因此，色氨酸营养不良体的选择显然不是由营养不良体和野生型之间能量效率的差异引起的。在进化过程中，能源效率的选择并没有传统假设的那么重要。
Evolution to auxotrophy can be explained by an efficiency argument which, formally stated as the energy conservation hypothesis, says that the rate of selection is determined by the amount of energy saved by eliminating unneeded processes. This hypothesis was tested using tryptophan mutants of E. coli competing against isogenic wild-type E. coli in a glucose-limited chemostat with excess tryptophan. The selection for the mutant was 3 orders of magnitude larger than the theoretical percentage of the energy budget which could be saved. No demographic differences could be found to explain this large selection. Predicted relative differences in selection rates between mutants in the same environment or the same mutant in different environments were not found. Therefore, the selection for tryptophan auxotrophs was apparently not caused by differences in energy efficiency between the auxotroph and wild-type. That selection for energy efficiency is less important in evolution than traditionally assumed is implied.