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

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.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2022 The Author(s).)