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.

中文翻译：

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圆环毛霉中 cAMP 介导的信号通路的二态机制。

Mucor circinelloides 是一种二形真菌，是一种属于接合菌纲的非病原体菌株。本研究从基因表达的角度报道了在CO2环境下M. circinelloides酵母样细胞诱导的部分假设机制。为了解释与菌株形态变化有关的一些基因的变化与表达之间的关系，通过实时qPCR对丝状细胞和酵母细胞进行了分析。比较的基因是 Nce103、Ras3、Cyr1、Pde 和 Efg1，分别编码碳酸酐酶、GTPase、腺苷酸环化酶、磷酸二酯酶和延伸因子 G1。在 70%N2+30%CO2 的厌氧生长酵母细胞中，Nce103 和 Ras3 基因表达下降至 24 小时，而丝状细胞的表达增加。然而，酵母细胞中Cyr1下游基因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的 Pde 水平表明细胞内 cAMP 积累。酵母细胞中的实际 cAMP 仍然存在，而丝状细胞中的实际 cAMP 随着培养而减少。控制菌丝伸长的 Efg1 表达水平在酵母细胞中受到抑制。细胞内 cAMP 积累和 Efg1 表达调节菌丝伸长或酵母形成。控制菌丝伸长的 Efg1 表达水平在酵母细胞中受到抑制。细胞内 cAMP 积累和 Efg1 表达调节菌丝伸长或酵母形成。控制菌丝伸长的 Efg1 表达水平在酵母细胞中受到抑制。细胞内 cAMP 积累和 Efg1 表达调节菌丝伸长或酵母形成。