College of Marine Life Sciences, Ocean University of China, Yushan-Road, No. 5, Qingdao, China.
Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China.
Microb Ecol. 2021 Jan;81(1):52-66. doi: 10.1007/s00248-020-01577-8. Epub 2020 Aug 17.
In this study, it was found that a Cre/loxP system could be successfully used as a tool for editing the genome of the psychrophilic yeast Metschnikowia australis W7-5 isolated from Antarctica. The deletion and over-expression of the TPS1 gene for trehalose biosynthesis, the GSY gene for glycogen biosynthesis, and the GPD1 and GPP genes for glycerol biosynthesis had no influence on cell growth of the mutants and transformants compared to cell growth of their wild-type strain M. australis W7-5, indicating that trehalose, glycogen, and glycerol had no function in growth of the psychrophilic yeast at different temperatures. However, removal of the SLT2 gene encoding the mitogen-activated protein kinase in the cell wall integrity (CWI) signaling pathway and the SWI4 and SWI6 genes encoding the transcriptional activators Swi4/6 had the crucial influence on cell growth of the psychrophilic yeast at the low temperature, especially at 25 °C and expression of the genes related to cell wall and lipid biosynthesis. Therefore, the cell wall could play an important role in growth of the psychrophilic yeast at different temperatures and biosynthesis of cell wall was actively regulated by the CWI signaling pathway. This was the first time to show that the genome of the psychrophilic yeast was successfully edited and the molecular evidences were obtained to elucidate mechanisms of low temperature growth of the psychrophilic yeast from Antarctica.
在这项研究中，发现 Cre/loxP 系统可成功用作编辑南极嗜冷酵母 Metschnikowia australis W7-5 基因组的工具。与野生型菌株 M. australis W7-5 的细胞生长相比，缺失和过表达海藻糖生物合成的 TPS1 基因、糖原生物合成的 GSY 基因以及甘油生物合成的 GPD1 和 GPP 基因对突变体和转化体的细胞生长没有影响，表明在不同温度下，海藻糖、糖原和甘油对嗜冷酵母的生长没有作用。然而，去除细胞壁完整性 (CWI) 信号通路中编码丝裂原激活蛋白激酶的 SLT2 基因以及编码转录激活因子 Swi4/6 的 SWI4 和 SWI6 基因对嗜冷酵母在低温下的细胞生长有至关重要的影响，特别是在 25°C 时，以及与细胞壁和脂质生物合成相关的基因的表达。因此，细胞壁在不同温度下的嗜冷酵母生长中可能发挥重要作用，细胞壁生物合成受到 CWI 信号通路的积极调控。这是首次成功编辑嗜冷酵母的基因组，并获得了阐明南极嗜冷酵母低温生长机制的分子证据。
