The Impact of Gene Dosage and Heterozygosity on The Diploid Pathobiont .

is a fungal species that can colonize multiple niches in the human host where it can grow either as a commensal or as an opportunistic pathogen. The genome of has long been of considerable interest, given that it is highly plastic and can undergo a wide variety of alterations. These changes play a fundamental role in determining traits and have been shown to enable adaptation both to the host and to antifungal drugs. isolates contain a heterozygous diploid genome that displays variation from the level of single nucleotides to largescale rearrangements and aneuploidy. The heterozygous nature of the genome is now increasingly recognized as being central to biology, as the relative fitness of isolates has been shown to correlate with higher levels of overall heterozygosity. Moreover, loss of heterozygosity (LOH) events can arise frequently, either at single polymorphisms or at a chromosomal level, and both can alter the behavior of cells during infection or can modulate drug resistance. In this review, we examine genome plasticity in this pathobiont focusing on how gene dosage variation and loss of heterozygosity events can arise and how these modulate behavior.