Temperature during conidiophore development primes Aspergillus fumigatus spore transcriptome for asexual or sexual development

A. fumigatus makes abundant asexual spores (conidia) which are widely distributed by wind and can be inhaled from the environment. In susceptible individuals inhaled conidia break dormancy, germinate and grow in the lung leading to serious disease.

Recent work has shown that conidia made at 37°C and 50°C have different morphologies and germination kinetics. While the asexual cycle is well-characterized at 37°C, much less is known about the asexual cycle at 50°C. Here, we combine flow cytometry and transcriptomics to track morphology and gene expression in the hyphae, conidiophores and conidia of A. fumigatus during asexual development at 37°C or 50°C. We show that the temperature during a narrow time window in late-stage conidiophore development dictates resulting conidial morphology, transcriptional program, and germination kinetics.