毛霉是一种双态真菌,属于合子菌的非病原体菌株。在这项研究中,从基因表达的角度报道了在CO2气氛中对M.circinelloides的酵母样细胞诱导的假设机制的一部分。为了解释菌株形态变化中某些基因的变化与表达之间的关系,通过实时qPCR对丝状和酵母细胞进行分析。比较的基因是Nce103,Ras3,Cyr1,Pde,Efg1编码碳酸酐酶,GTPase,腺苷酸环化酶,磷酸二酯酶,和伸长因子G1。在具有70%N230%CO2的厌氧生长酵母细胞中,Nce103和Ras3基因表达降低至24小时,而丝状细胞的表达增加。然而,Cyr1下游基因在酵母细胞中的表达水平高于丝状细胞。酵母细胞中Pde的水平低于丝状细胞,表明细胞内cAMP的积累。酵母细胞中的实际cAMP保留,而丝状细胞的cAMP随培养而减少。控制菌丝伸长的Efg1表达水平在酵母细胞中被抑制。细胞内cAMP积累和Efg1表达调节菌丝伸长或酵母形成。
Mucor circinelloides is a dimorphic fungus that is a non-pathogen strain belonging to zygomycetes. In this research, a part of hypothetical mechanism on yeast-like cell induction of M. circinelloides in CO2 atmosphere was reported from the viewpoint of gene expression. To explain the relation between the change and the expressions of some genes involved in morphological changes of the strain, these were analyzed on the filamentous and yeast cell by real-time qPCR. The compared genes were Nce103, Ras3, Cyr1, Pde, and Efg1 encoding carbonic anhydrase, GTPase, adenylate cyclase, phosphodiesterase, and elongation factor G1, respectively. In anaerobic grown yeast cell with 70%N2 + 30%CO2, the Nce103 and Ras3 gene expressions decreased to 24 h whereas that of the filamentous cell increased. However, a downstream gene of Cyr1 expression level in the yeast cell was higher than that of filamentous cell. A lower level of Pde in the yeast cell than that of the filamentous cell indicated intracellular cAMP accumulation. The actual cAMP in the yeast cell remained whereas that of the filamentous cell decreased with cultivation. The Efg1 expression level controlling hyphal elongation was suppressed in the yeast cell. The intracellular cAMP accumulation and Efg1 expression regulate hyphal elongation or yeast forming.