In vivo RNA sequencing identifies the lncRNA ReLoV critical for morphological transition and virulence in Candida albicans I

We identified ReLoV, an uncharacterized lncRNA, whose expression was significantly induced upon in vivo infection. The relov Δ/Δ mutant failed to develop elongated filaments in murine kidneys and displayed an attenuated virulence in a systemic infection model. The expression of ReLoV was also increased in response to multiple filament-inducing stimuli, including serum, neutral pH (Lee’s) and rapamycin.

ReLoV was critical for hyphal maintenance, but is dispensable to initiate hypha formation. The lack of ReLoV reduced the transcript of UME6, a hypha-specific transcriptional activator that controls the level and duration of hypha-specific transcription, during hyphal elongation but not initiation. We suggest that misregulation of UME6 level in the relov Δ/Δ mutant causes its defects in hyphal development during invasive infection, as well as under in vitro hypha-inducing conditions.

Collectively, these data uncover the lncRNA ReLoV as an additional layer of genetic regulation of morphogenesis and pathogenesis in C. albicans.