Bacher Jamie M, Metzgar David, de Crécy-Lagard Valérie
Skaggs Institute for Chemical Biology and Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., BCC-379, La Jolla, CA 92037, USA.
J Bacteriol. 2006 Dec;188(24):8534-42. doi: 10.1128/JB.00846-06. Epub 2006 Oct 6.
The reason for genetic exchange remains a crucial question in evolutionary biology. Acinetobacter baylyi strain ADP1 is a highly competent and recombinogenic bacterium. We compared the parallel evolution of wild-type and engineered noncompetent lineages of A. baylyi in the laboratory. If transformability were to result in an evolutionary benefit, it was expected that competent lineages would adapt more rapidly than noncompetent lineages. Instead, regardless of competency, lineages adapted to the same extent under several laboratory conditions. Furthermore, competent lineages repeatedly evolved a much lower level of transformability. The loss of competency may be due to a selective advantage or the irreversible transfer of loss-of-function alleles of genes required for transformation within the competent population.
基因交换的原因仍是进化生物学中的一个关键问题。拜氏不动杆菌ADP1菌株是一种高度感受态且具有重组能力的细菌。我们在实验室中比较了拜氏不动杆菌野生型和工程改造的非感受态谱系的平行进化。如果可转化性能带来进化优势，那么预期感受态谱系会比非感受态谱系更快适应。然而，无论是否具有感受态，在几种实验室条件下谱系的适应程度相同。此外，感受态谱系反复进化出低得多的可转化性水平。感受态的丧失可能是由于选择优势或功能丧失等位基因在感受态群体中不可逆的转移，这些等位基因是转化所需基因的。
