Transcriptomic characterization of Coccidioides morphological states using RiboMarker-enhanced RNA sequencing

Area of Science:

• Mycology
• Molecular Biology
• Pathogenomics

Background:

• Coccidioides causes Valley fever, a significant mammalian disease.
• Small RNAs (sRNAs) regulate virulence in pathogenic fungi but are unexplored in Coccidioides.
• Understanding Coccidioides life cycle transitions is key to controlling infections.

Purpose of the Study:

• To profile small RNA (sRNA) and RNA fragment expression across Coccidioides posadasii life stages.
• To investigate intracellular and extracellular RNA fractions during morphological transitions.
• To identify novel RNA species involved in Coccidioides virulence and host interaction.

Main Methods:

• Small RNA sequencing using RiboMarker®️ for enhanced transcriptome coverage.
• Analysis of arthroconidia, mycelia, and spherule morphologies.
• Comparison of intracellular and extracellular RNA pools.

Main Results:

• Significant transcriptomic remodeling observed during arthroconidia-to-mycelia/spherule transitions.
• Identification of sRNA and fragment-producing loci potentially involved in life cycle progression.
• Distinct RNA fragmentation patterns linked to specific morphological states.
• Detection of extracellular RNA export, including snRNAs and tRNA fragments, suggesting communication roles.

Conclusions:

• An atlas of intra- and extracellular Coccidioides sRNAs and fragments was generated.
• These findings provide insights into Coccidioides virulence and life cycle regulation.
• Identified RNA species offer potential for Valley fever biomarker discovery.