Rapid gain and loss of a chromosome drives key morphology and virulence phenotypes in the fungal pathogen Histoplasma.

ABSTRACT: Heritable phenotypic switches are fundamental to the ability of cells to respond to specific conditions. Such switches are key to the success of environmental pathogens, which encounter disparate conditions as they transition between the environment and host. We determine that the copy number of chromosome seven in the thermally dimorphic fungus Histoplasma dramatically affects the rate of transition. Though Histoplasma is haploid, a second copy of this chromosome is present in natural isolates of multiple Histoplasma species and is gained and lost at a high rate. Cells carrying two copies of this chromosome exhibit aspects of the environmental transcriptome even under host-like conditions and have a competitive advantage in the transition to the environmental form. Conversely, these cells

SUBMITTER: Heater S 

PROVIDER: S-EPMC12788632 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature