title: Cell wall biogenesis in a double chitin synthase mutant (chsG-/chsE-) of Aspergillus fumigatus.
abstract: Previous studies (Aufauvre-Brown et al., 1997; Mellado et al., 1996a,b ) have shown that only two genes of the Aspergillus fumigatus chitin synthase family, chsG and chsE, play a role in the morphogenesis of this fungal species. An A. fumigatus strain lacking both chsG (class III CHS) and chsE (class V CHS) genes was constructed by gene replacement of the chsE gene with a copy that has its conserved coding region interrupted by the hph resistance cassette in an A. fumigatus chsG- genetic background. Unexpectedly the double disruption was not lethal. The double mutant AfchsG-/chsE- strain (i) has reduced chitin synthase activity with or without trypsin stimulation, (ii) has a reduced colony radial growth rate, (iii) produces highly branched hyphae, (iv) exhibits aberrant features, such as periodic swellings along the length of the hyphae and a block in conidiation that can be partially restored by an osmotic stabilizer (v) shows alterations in the shape and germination capacity of the conidia, and (vi) has a cell wall that contains half the chitin of the parental strain and is, unexpectedly, highly enriched in alpha-(1-3) glucan.
authors.affiliation: Unidad de Micología, Centro Nacional de Microbiología, Institute de Salud Carlos III, Carretera Majadahonda-Pozuelo Km2, Majadahonda, 28220, Madrid, Spain. emallado@isciii.es
authors.forename: E
authors.initials: E
authors.lastname: Mellado
authors.forename: G
authors.initials: G
authors.lastname: Dubreucq
authors.forename: P
authors.initials: P
authors.lastname: Mol
authors.forename: J
authors.initials: J
authors.lastname: Sarfati
authors.forename: S
authors.initials: S
authors.lastname: Paris
authors.forename: M
authors.initials: M
authors.lastname: Diaquin
authors.forename: D W
authors.initials: DW
authors.lastname: Holden
authors.forename: J L
authors.initials: JL
authors.lastname: Rodriguez-Tudela
authors.forename: J P
authors.initials: JP
authors.lastname: Latgé
mesh_terms: D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism*; D002686:Chitin / Q000096:biosynthesis* / Q000378:metabolism; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D005800:Genes, Fungal / Q000235:genetics*; D009154:Mutation
chemical_list: D002686:Chitin; D002687:Chitin Synthase