Department of Microbiology, Washington State University, Pullman, Washington 99164-4340.
Appl Environ Microbiol. 1989 May;55(5):1136-43. doi: 10.1128/aem.55.5.1136-1143.1989.
A highly polymorphic Xenorhabdus luminescens strain was isolated. The primary form of X. luminescens was luminescent and nonswarming and produced a yellow pigment and antimicrobial substances. The primary form generated a secondary form that had a distinct orange pigmentation, was weakly luminescent, and did not produce antimicrobial substances. Both the primary and secondary forms generated a set of colony variants at frequencies that exceeded normal rates for spontaneous mutation. The variant forms include nonswarming and swarming forms that formed large colonies and a small-colony (SC) form. The primary and secondary forms generated their SC forms at frequencies of between 1 and 14% and 1 and 2%, respectively. The SC forms were distinct from their parental primary and secondary forms in colony and cellular morphology and in protein composition. The cellular morphology and protein patterns of the nonswarming and swarming colony variants were all very similar. The DNA fingerprints of all forms were similar. Each SC-form colony reverted at high frequency to the form from which it was derived. The proportion of parental-type cells in the SC-form colonies varied with age, with young colonies containing as few as 0.0002% parental-type cells. The primary-to-secondary switch was stable, but all the other colony forms were able to switch at high frequencies to the alternative colony phenotypes.
一种高度多态的发光杆菌（Xenorhabdus luminescens）菌株被分离出来。发光杆菌的主要形式是发光的非游动型，不产生抗菌物质，产生黄色色素。主要形式产生次要形式，具有明显的橙色色素沉着，微弱发光，不产生抗菌物质。主要形式和次要形式都以超过自发突变正常频率的频率产生一组菌落变体。变体形式包括非游动型和游动型，形成大菌落和小菌落（SC）形式。主要形式和次要形式分别以 1%至 14%和 1%至 2%的频率产生 SC 形式。SC 形式在菌落和细胞形态以及蛋白质组成上与亲本的主要形式和次要形式明显不同。非游动型和游动型菌落变体的细胞形态和蛋白质模式非常相似。所有形式的 DNA 指纹图谱都相似。所有 SC 形式的菌落都以高频率回复到其来源形式。SC 形式菌落中亲代细胞的比例随年龄而变化，年轻的菌落中亲代细胞的比例低至 0.0002%。从主要形式到次要形式的转变是稳定的，但所有其他的菌落形式都能够以高频率转变为替代的菌落表型。
