Data from: Destabilizing mutations encode nongenetic variation that drives evolutionary innovation

Evolutionary innovations are often achieved by repurposing existing genes to perform new functions; however, the mechanisms enabling the transition from old to new remain controversial. We identified mutations in bacteriophage λ’s host-recognition gene J that confer enhanced adsorption to λ’s native receptor, LamB, and the ability to access a new receptor, OmpF. The mutations destabilize particles and cause conformational bistability of J, which yields progeny of multiple phenotypic forms, each proficient at different receptors. This work provides an example of how nongenetic protein variation can catalyze an evolutionary innovation. We propose that cases where a single genotype can manifest as multiple phenotypes may be more common than previously expected and offer a general mechanism for evolutionary innovation.进化创新往往通过重新利用现有基因以执行新功能来实现；然而，驱动从旧功能到新功能转变的机制仍存在争议。我们在λ噬菌体（bacteriophage λ）的宿主识别基因J（host-recognition gene J）中鉴定出了一类突变，这类突变不仅可增强噬菌体对其天然受体LamB的吸附能力，还使其获得了结合新受体OmpF的能力。这些突变会使噬菌体颗粒不稳定，并引发J蛋白的构象双稳态，进而产生多种表型的子代噬菌体，每种表型都能高效结合不同的受体。本研究为非遗传蛋白质变异（nongenetic protein variation）如何催化进化创新提供了一个典型案例。我们提出，单个基因型（genotype）可表现为多种表型（phenotype）的情况可能比此前预期的更为普遍，这为进化创新提供了一种通用机制。