The <i>velvet</i> Regulator VosA Governs Survival and Secondary Metabolism of Sexual Spores in <i>Aspergillus nidulans</i>

• Main Authors: Min-Ju Kim, Mi-Kyung Lee, Huy Quang Pham, Myeong Ju Gu, Bohan Zhu, Sung-Hun Son, Dongyup Hahn, Jae-Ho Shin, Jae-Hyuk Yu, Hee-Soo Park, Kap-Hoon Han
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Genes
• Subjects: vosa; sexual development; ascospores; <i>aspergillus nidulans</i>
• Online Access: https://www.mdpi.com/2073-4425/11/1/103

The <i>velvet</i> regulator VosA plays a pivotal role in asexual sporulation in the model filamentous fungus <i>Aspergillus nidulans</i>. In the present study, we characterize the roles of VosA in sexual spores (ascospores) in <i>A</i>. <i>nidulans</i>. During ascospore maturation, the deletion of <i>vosA</i> causes a rapid decrease in spore viability. The absence of <i>vosA</i> also results in a lack of trehalose biogenesis and decreased tolerance of ascospores to thermal and oxidative stresses. RNA-seq-based genome-wide expression analysis demonstrated that the loss of <i>vosA</i> leads to elevated expression of sterigmatocystin (ST) biosynthetic genes and a slight increase in ST production in ascospores. Moreover, the deletion of <i>vosA</i> causes upregulation of additional gene clusters associated with the biosynthesis of other secondary metabolites, including asperthecin, microperfuranone, and monodictyphenone. On the other hand, the lack of <i>vosA</i> results in the downregulation of various genes involved in primary metabolism. In addition, <i>vosA</i> deletion alters mRNA levels of genes associated with the cell wall integrity and trehalose biosynthesis. Overall, these results demonstrate that the <i>velvet</i> regulator VosA plays a key role in the maturation and the cellular and metabolic integrity of sexual spores in <i>A. nidulans</i>.