Abstract：
The complex morphological structure of Aspergillus niger influences its production of proteins, metabolites, etc., making the genetic manipulation and clonal purification of this species increasingly difficult, especially in aconidial Aspergillus niger. In this study, we found that N-acetyl-D-glucosamine (GlcNAc) could induce the formation of spore-like propagules in the aconidial Aspergillus niger SH2 strain. The spore-like propagules possessed life activities such as drug resistance, genetic transformation, and germination. Transcriptomic analysis indicated that the spore-like propagules were resting conidia entering dormancy and becoming more tolerant to environmental stresses. The Dac1 gene and the metabolic pathway of GlcNAc converted to glycolysis are related to the formation of the spore-like propagules, as evidenced by the CRISPRi system, qPCR, and semi-quantitative RT-PCR. Moreover, a method based on the CRISPR-Cas9 tool to rapidly recycle screening tags and recover genes was suitable for Aspergillus niger SH2. To sum up, this suggests that the spore-like propagules are resting conidia and the mechanism of their formation is the metabolic pathway of GlcNAc converted to glycolysis, particularly the Dac1 gene. This study can improve our understanding of the critical factors involved in mechanisms of phenotypic change and provides a good model for researching phenotypic change in filamentous fungi.
摘要：
黑曲霉复杂的形态结构影响其蛋白质产量,代谢物，等。,使得该物种的遗传操作和克隆纯化变得越来越困难，尤其是在黑曲霉中。在这项研究中,我们发现N-乙酰-D-葡糖胺（GlcNAc）可以诱导黑曲霉SH2菌株中孢子样繁殖体的形成。类孢子繁殖体具有耐药性等生命活动,遗传转化,和发芽。转录组学分析表明，孢子样繁殖体是静止的分生孢子，进入休眠并对环境压力更具耐受性。Dac1基因和GlcNAc转化为糖酵解的代谢途径与孢子样繁殖体的形成有关，正如CRISPRI系统所证明的那样，qPCR,和半定量RT-PCR。此外，一种基于CRISPR-Cas9工具的快速回收筛选标签和回收基因的方法适用于黑曲霉SH2.总而言之,这表明孢子样繁殖体是静止的分生孢子，其形成机制是GlcNAc转化为糖酵解的代谢途径，特别是Dac1基因。本研究可以提高我们对表型变化机制中的关键因素的理解，为研究丝状真菌的表型变化提供一个良好的模型。
