title: Carbon dioxide is a powerful inducer of monokaryotic hyphae and spore development in Cryptococcus gattii and carbonic anhydrase activity is dispensable in this dimorphic transition.
abstract: Cryptococcus gattii is unique among human pathogenic fungi with specialized ecological niche on trees. Since leaves concentrate CO2, we investigated the role of this gaseous molecule in C. gattii biology and virulence. We focused on the genetic analyses of β-carbonic anhydrase (β-CA) encoded by C. gattii CAN1 and CAN2 as later is critical for CO2 sensing in a closely related pathogen C. neoformans. High CO2 conditions induced robust development of monokaryotic hyphae and spores in C. gattii. Conversely, high CO2 completely repressed hyphae development in sexual mating. Both CAN1 and CAN2 were dispensable for CO2 induced morphogenetic transitions. However, C. gattii CAN2 was essential for growth in ambient air similar to its reported role in C. neoformans. Both can1 and can2 mutants retained full pathogenic potential in vitro and in vivo. These results provide insight into C. gattii adaptation for arboreal growth and production of infectious propagules by β-CA independent mechanism(s).
authors.affiliation: Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, New York, United States of America.
authors.forename: Ping
authors.initials: P
authors.lastname: Ren
authors.affiliation: Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, New York, United States of America; Department of Biomedical Sciences, School of Public Health, State University at New York, Albany, New York, United States of America.
authors.forename: Vishnu
authors.initials: V
authors.lastname: Chaturvedi
authors.affiliation: Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, New York, United States of America; Department of Biomedical Sciences, School of Public Health, State University at New York, Albany, New York, United States of America.
authors.forename: Sudha
authors.initials: S
authors.lastname: Chaturvedi
mesh_terms: D002245:Carbon Dioxide / Q000494:pharmacology; D002256:Carbonic Anhydrases / Q000096:biosynthesis*; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D056285:Cryptococcus gattii / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D006801:Humans; D025301:Hyphae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D009154:Mutation; D012098:Reproduction / Q000187:drug effects; D013170:Spores / Q000254:growth & development*
chemical_list: D002245:Carbon Dioxide; D002256:Carbonic Anhydrases