Although dynamins and dynamin-related proteins (DRPs), a large GTPase superfamily, are involved in the budding of transport vesicles and division of organelles in eukaryotic cells, the function of these proteins in entomopathogenic fungi has not been reported to date. Here, DNM1, a DRP in Metarhizium robertsii, was characterized using gene disruption and complementation strategies. Mutant phenotype assays showed that the ΔDnm1 strain displayed increased defects in radial growth (∼24%) and conidial production (∼42%) compared to those of the wild type (WT), and reduced conidiation levels were accompanied by the repression of several key conidiation-related genes, including flbA, wetA, and flbD. Additionally, mutant bioassays revealed that disruption of Dnm1 impaired the virulence (both topical inoculation and injection) of M. robertsii in the insect Galleria mellonella. Further analysis demonstrated that deleting Dnm1 in fungi suppressed the transcriptional levels of several virulence genes in the insect hemocoel. Moreover, we found that DNM1 colocalized with peroxisomes and mitochondria. Importantly, disruption of Dnm1 abolished normal fungal endocytosis, resulting in significantly decreased numbers of, as well as morphological changes in, peroxisomes. These findings indicate that deletion of Dnm1 causes significant changes in the vegetative growth, sporulation, and virulence of M. robertsii due to changes in cell function and peroxisomes.

中文翻译：

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DNM1是一种与动力蛋白有关的蛋白，可促进内吞作用和过氧化物酶体的分裂，是罗伯茨氏菌的营养生长，孢子形成和致病力所必需的。

尽管动力蛋白和动力蛋白相关蛋白（DRPs）（一个大的GTPase超家族）参与真核细胞中运输小泡的萌芽和细胞器的分裂，但至今尚未报道这些蛋白在昆虫病原真菌中的功能。在这里，DNM1，在DRP绿僵菌robertsii，用基因破坏和互补的战略特点。突变表型分析显示，与野生型（WT）相比，ΔDnm1菌株在径向生长（〜24％）和分生孢子（〜42％）上显示出增加的缺陷，并且降低的分生孢子水平伴随着数种抑制关键与构象相关的基因，包括flbA，wetA和flbD。此外，突变体的生物测定揭示了该中断DNM1受损的毒力（包括局部接种和注射）M. robertsii在昆虫蜡螟。进一步的分析表明，删除真菌中的Dnm1可以抑制昆虫血细胞中几个毒力基因的转录水平。此外，我们发现DNM1与过氧化物酶体和线粒体共定位。重要的是，Dnm1的破坏消除了正常的真菌内吞作用，导致过氧化物酶体的数量显着减少以及形态变化。这些发现表明Dnm1的删除由于细胞功能和过氧化物酶体的变化，导致罗伯茨罗非鱼的营养生长，孢子形成和毒力发生显着变化。