Abstract:[Background] Talaromyces marneffei is an important lethal pathogenic fungus. [Objective]To investigate the basic characteristics and expression patterns of the Septin gene family in T. marneffei. [Methods] In this study, bioinformatics methods were used to identify the members of the Septin gene family in T. marneffei and analyze gene structure, physicochemical properties, secondary and tertiary structure, and subcellular localization. Additionally, real-time fluorescence quantitative PCR was employed to analyze the expression of the Septin gene family in the mycelial phases and yeast phases, respectively. [Results] This paper identified 5 members of the Septin gene family, with amino acid lengths ranging from 346 to 575 aa. All members possess GTP-CDC binding domains and are hydrophilic proteins. Subcellular localization was mainly located in the cell nucleus and mitochondrial matrix. The secondary structure is mainly composed of α-helices and random coils, with a complex tertiary structure. The core Septin is highly conserved among different pathogenic fungi. The mRNA expression levels of TmSep2 and TmSep4 were significantly higher in the yeast phase compared to the mycelial phase, while the mRNA expression level of TmSep5 was significantly lower. The mRNA expression levels of TmSep1 and TmSep3 showed a slight increase in the yeast phase compared to the mycelial phase but without significant differences. [Conclusion] The expression of Septin genes varies in different phases of T. marneffei during the dimorphic transition, with some significant differences, which implies the potential roles of Septin in the dimorphic transition and pathogenesis of T. marneffei. This study provides a theoretical basis for further exploration of the functions and regulatory mechanisms of Septin in T. marneffei.
