Swanson J, Bergstrom S, Boslego J, Koomey M
NIH, NIAID, LMSF, Rocky Mountain Labs, Hamilton, MT.
Antonie Van Leeuwenhoek. 1987;53(6):441-6. doi: 10.1007/BF00415500.
Pilus+ "wild-type" gonococci (Gc) frequently display gene conversion of their expressed complete pilin gene (CPG); a copy of DNA derived from one of the Gc genome's multiple silent partial pilin genes (PPG) is recombinationally-inserted into the CPG's central and 3' portions with formation of a new, chimeric CPG. Expression of that new CPG leads to either 1) retention of pilus+ phenotype but change in pilin primary structure/antigenicity, or 2) phase change to pilus- phenotype capable of reverting. This study utilizes pilus revertants of P-rp +/- Gc and P+ colony morphotype variants spawned by P++ Gc to examine pilin gene conversion in strain MS11mk Gc in greater detail. Each revertant's and variant's expressed pilin gene's sequence (as pilin mRNA) was defined to learn whether their differences are due to gene conversion by different PPGs, or by varying stretches from the same PPG, or both. Gene conversion by PPG pilS1 copy 2 has been documented in Gc recovered from a human volunteer's urethra previously inoculated with pilus Gc (strain MS11). The pilus+ Gc isolated expressed structurally/antigenically distinct pilins.
菌毛阳性的“野生型”淋球菌（Gc）经常表现出其表达的完整菌毛蛋白基因（CPG）的基因转换；从Gc基因组多个沉默的部分菌毛蛋白基因（PPG）之一衍生的DNA拷贝通过重组插入CPG的中央和3'部分，形成新的嵌合CPG。该新CPG的表达导致：1）菌毛阳性表型得以保留，但菌毛蛋白一级结构/抗原性发生改变；或者2）发生相变，转变为能够回复的菌毛阴性表型。本研究利用P-rp +/- Gc的菌毛回复突变体以及由P++ Gc产生的P+菌落形态变体，更详细地研究MS11mk Gc菌株中的菌毛蛋白基因转换。确定每个回复突变体和变体表达的菌毛蛋白基因的序列（作为菌毛蛋白mRNA），以了解它们之间的差异是由于不同PPG的基因转换，还是同一PPG的不同片段，或者两者兼而有之。之前在从一名预先接种过菌毛Gc（菌株MS11）的人类志愿者尿道中分离出的Gc中，已证明PPG pilS1拷贝2可进行基因转换。分离出的菌毛阳性Gc表达结构/抗原性不同的菌毛蛋白。
