The transcription factor EFG1 functions as a suppressor of white-to-opaque and white-to-gray switching in a/α strains of Candida albicans In a collection of 27 clinical isolates, 4 of the 17 EFG1/EFG1 strains, 1 of the 2 EFG1/efg1 strains, and all 8 of the efg1/efg1 strains underwent white-to-opaque switching. The four EFG1/EFG1 strains, the one EFG1/efg1 strain, and one of the eight efg1/efg1 strains that underwent switching to opaque did not switch to gray and could not be complemented with a copy of EFG1 Competition experiments in a mouse model for gastrointestinal (GI) colonization confirmed that efg1/efg1 cells rapidly outcompete EFG1/EFG1 cells, and in plating experiments, formed colonies containing both gray and opaque cells. Direct microscopic analysis of live cells in the feces, however, revealed that the great majority of cells were opaque, suggesting opaque, not gray, may be the dominant phenotype at the site of colonization.IMPORTANCE Close to half of a collection of 27 clinical a/α isolates of Candida albicans underwent white-to-opaque switching. Complementation experiments revealed that while approximately half of the a/α switchers were due to EFG1 mutations, the remaining half were due to mutations in other genes. In addition, the results of competition experiments in a mouse GI tract colonization model support previous observations that efg1/efg1 cells rapidly outcompete EFG1/EFG1 strains, but direct microscopic analysis reveals that the major colonizing cells were opaque, not gray.

中文翻译：

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EFG1突变，表型转换和白色念珠菌临床a /α菌株定植。

转录因子EFG1在白色念珠菌的a /α菌株中起白色至不透明和白色至灰色转换的抑制作用。在27种临床分离株的集合中，17种EFG1 / EFG1菌株中有4种，2种中的1种EFG1 / efg1菌株，以及所有8个efg1 / efg1菌株均经历了白变转换。四种EFG1 / EFG1菌株，一种EFG1 / efg1菌株和八种efg1 / efg1菌株中的一种已变为不透明，它们不能转换为灰色，并且不能与EFG1的复制品互补。胃肠道（GI）定植证实efg1 / efg1细胞迅速超过EFG1 / EFG1细胞，在平板实验中，形成了既包含灰色细胞又包含不透明细胞的菌落。但是直接对粪便中的活细胞进行显微镜分析 揭示大多数细胞是不透明的，表明不透明而不是灰色可能是定殖位点的显性表型。重要27种临床白色念珠菌a /α分离株中有近一半经历了白色至不透明交换。补充实验表明，虽然大约一半的a /α切换子是由于EFG1突变引起的，但其余的一半是由于其他基因的突变引起的。另外，在小鼠胃肠道定植模型中的竞争实验结果支持以前的观察，即efg1 / efg1细胞迅速超过EFG1 / EFG1菌株，但直接的显微镜分析显示主要的定殖细胞是不透明的，不是灰色的。重要事项白色念珠菌的27种临床a /α分离株中有近一半经历了白变转换。补充实验表明，虽然大约一半的a /α切换子是由于EFG1突变引起的，但其余的一半是由于其他基因的突变引起的。另外，在小鼠胃肠道定植模型中的竞争实验结果支持以前的观察，即efg1 / efg1细胞迅速超过EFG1 / EFG1菌株，但直接的显微镜分析显示主要的定殖细胞是不透明的，不是灰色的。重要事项白色念珠菌的27种临床a /α分离株中有近一半经历了白变转换。补充实验表明，虽然大约一半的a /α切换子是由于EFG1突变引起的，但其余的一半是由于其他基因的突变引起的。另外，在小鼠胃肠道定植模型中的竞争实验结果支持以前的观察，即efg1 / efg1细胞迅速超过EFG1 / EFG1菌株，但直接的显微镜分析显示主要的定殖细胞是不透明的，不是灰色的。