Phenotype to genotype in Neurospora crassa: Association of the scumbo phenotype with mutations in the gene encoding ceramide C9-methyltransferase

Erin L Bredeweg; Kevin McCluskey; Scott E Baker

doi:10.1016/j.crmicr.2022.100117

Phenotype to genotype in Neurospora crassa: Association of the scumbo phenotype with mutations in the gene encoding ceramide C9-methyltransferase

Curr Res Microb Sci. 2022 Feb 19:3:100117. doi: 10.1016/j.crmicr.2022.100117. eCollection 2022.

Authors

Erin L Bredeweg¹, Kevin McCluskey², Scott E Baker^{1

3}

Affiliations

¹ Functional and Systems Biology Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA.
² Fungal Genetics Stock Center, Kansas State University, USA.
³ DOE Joint BioEnergy Institute, Emeryville, CA, USA.

Abstract

Using a legacy of genetic mutants of Neurospora crassa, paired with resequencing efforts through JGI, we have identified the gene responsible for the 'scumbo' mutant. This early morphological mutant was described as "Irregular flat, spreading growth with knobby protrusions and abnormal conidiation, but no free conidia. Mycelium usually appears yellowish rather than orange. Female fertile." (Perkins, Radford et al. 2000). Our further investigation has found new insights into the identity and associated functions of scumbo as a ceramide C9 methyltransferase, previously annotated as "similar to cyclopropane-fatty-acyl-phospholipidsynthase", encoded by the gene NCU07859. This enzyme performs a fungal-specific methyl modification of glycosyl-ceramides and has implications for membrane homeostasis and hyphal polarity in filamentous fungi.

Keywords: Ceramide C9-methyltransferase; Fast-forward genetics; Fungal genetics; Fungal genomics; Fungi; Morphology; Neurospora; Scumbo.