Chen Meng, Lyu Yufei, Feng Erling, Zhu Li, Pan Chao, Wang Dongshu, Liu Xiankai, Wang Hengliang
State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijng 100071, China.
Microorganisms. 2020 Apr 10;8(4):548. doi: 10.3390/microorganisms8040548.
The spore constitutes the infectious form of the bacterium, and sporulation is an important process in the organism's life cycle. Herein, we show that disruption of SpoVG resulted in defective sporulation. Confocal microscopy demonstrated that a Δ mutant could not form an asymmetric septum, the first morphological change observed during sporulation. Moreover, levels of mRNA were reduced in the mutant, as demonstrated using β-galactosidase activity assays. The effects on sporulation of the Δ mutation differed in from those in because of the redundant functions of SpoVG and SpoIIB in SpoVG is highly conserved between and . Conversely, BA4688 (the protein tentatively assigned as SpoIIB in ) and SpoIIB (SpoIIB) share only 27.9% sequence identity. On complementation of the Δ strain with , the resulting strain pB/Δ could not form resistant spores, but partially completed the prespore engulfment stage. In agreement with this finding, mRNA levels of the prespore engulfment gene were significantly increased in strain pB/Δ compared with the Δ strain. Transcription of the coat development gene was similar in the pB/Δ and Δ strains. Thus, unlike in , SpoVG appears to be required for sporulation in , which provides further insight into the sporulation mechanisms of this pathogen.
芽孢是该细菌的感染形式，芽孢形成是该生物体生命周期中的一个重要过程。在此，我们表明SpoVG的破坏导致芽孢形成缺陷。共聚焦显微镜显示，一个Δ突变体无法形成不对称隔膜，这是芽孢形成过程中观察到的第一个形态变化。此外，如使用β-半乳糖苷酶活性测定所证明的，该突变体中的mRNA水平降低。由于SpoVG和SpoIIB在中的冗余功能，Δ突变对芽孢形成的影响在与中有所不同。SpoVG在和之间高度保守。相反，BA4688（在中暂时指定为SpoIIB的蛋白质）和SpoIIB（SpoIIB）仅具有27.9%的序列同一性。用对Δ菌株进行互补时，所得菌株pB/Δ无法形成抗性芽孢，但部分完成了前芽孢吞噬阶段。与这一发现一致，与Δ菌株相比，菌株pB/Δ中前芽孢吞噬基因的mRNA水平显著增加。外壳发育基因的转录在pB/Δ和Δ菌株中相似。因此，与中不同，SpoVG似乎是中芽孢形成所必需的，这为深入了解这种病原体的芽孢形成机制提供了进一步的见解。
