Comparative genomic and transcriptomic analysis of wangiella dermatitidis, a major cause of phaeohyphomycosis and a model black yeast human pathogen.
Black or dark brown (phaeoid) fungi cause cutaneous, subcutaneous, and systemic infections in humans. Black fungi thrive in stressful conditions such as intense light, high radiation, and very low pH. Wangiella (Exophiala) dermatitidis is arguably the most studied phaeoid fungal pathogen of humans. Here, we report our comparative analysis of the genome of W. dermatitidis and the transcriptional response to low pH stress. This revealed that W. dermatitidis has lost the ability to synthesize alpha-glucan, a cell wall compound many pathogenic fungi use to evade the host immune system. In contrast, W. dermatitidis contains a similar profile of chitin synthase genes as related fungi and strongly induces genes involved in cell wall synthesis in response to pH stress. The large portfolio of transporters may provide W. dermatitidis with an enhanced ability to remove harmful products as well as to survive on diverse nutrient sources. The genome encodes three independent pathways for producing melanin, an ability linked to pathogenesis; these are active during pH stress, potentially to produce a barrier to accumulated oxidative damage that might occur under stress conditions. In addition, a full set of fungal light-sensing genes is present, including as part of a carotenoid biosynthesis gene cluster. Finally, we identify a two-gene cluster involved in nucleotide sugar metabolism conserved with a subset of fungi and characterize a horizontal transfer event of this cluster between fungi and algal viruses. This work reveals how W. dermatitidis has adapted to stress and survives in diverse environments, including during human infections.
Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142.
Zehua
Z
Chen
Diego A
DA
Martinez
Sharvari
S
Gujja
Sean M
SM
Sykes
Qiandong
Q
Zeng
Paul J
PJ
Szaniszlo
Zheng
Z
Wang
Christina A
CA
Cuomo
D002473:Cell Wall / Q000378:metabolism; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism; D055028:Comparative Genomic Hybridization; D005093:Exophiala / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D008040:Genetic Linkage; D016681:Genome, Fungal; D023281:Genomics; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008543:Melanins / Q000096:biosynthesis; D005810:Multigene Family; D018384:Oxidative Stress; D060446:Phaeohyphomycosis / Q000382:microbiology*; D010802:Phylogeny; D017423:Sequence Analysis, RNA
D005656:Fungal Proteins; D008543:Melanins; D002687:Chitin Synthase
RNA-Seq; cell wall biosynthesis; comparative genomics; horizontal gene transfer; human pathogenic fungi