title: Structural character evolution in Pucciniomycotina: mitosis, septa, and hyphal branch initiation in two Helicogloea species.
abstract: Early diverging taxa of Ascomycota and Basidiomycota share similarities in subcellular characters of the spindle pole body (SPB), nuclear division, and septal pore apparatus, but our understanding of character evolution is incomplete because of the limited number of structural studies within the earliest diverging subphyla of Dikarya, Taphrinomycotina and Pucciniomycotina. Two species of Helicogloea (Atractiellomycetes) were analyzed for these characters and provide data on SPB and nuclear division for an additional class of Pucciniomycotina. A detailed analysis of septal pore apparatus for the Helicogloea species permits comparisons with those of other Pucciniomycotina and Ascomycota. The endogenous origin of hyphal branches is shown to occur in a third class of Pucciniomycotina. The full set of characters supports a close relationship between Atractiellomycetes and Pucciniomycetes.
authors.affiliation: a Department of Plant and Microbial Biology , University of Minnesota , 1445 Gortner Avenue, St. Paul , Minnesota 55108.
authors.forename: David J
authors.initials: DJ
authors.lastname: McLaughlin
authors.affiliation: b Department of Botany , The Zamorin's Guruvayurappan College , Calicut , Kerala 673014 , India.
authors.forename: T K Arun
authors.initials: TK
authors.lastname: Kumar
authors.affiliation: c Landcare Research , 231 Morrin Road, St Johns Auckland 1072 , New Zealand.
authors.forename: Mahajabeen
authors.initials: M
authors.lastname: Padamsee
authors.affiliation: d Department of Botany and Plant Pathology , Purdue University , West Lafayette , Indiana 47907.
authors.forename: Merje
authors.initials: M
authors.lastname: Toome-Heller
authors.affiliation: e Department of Biology , University of Wisconsin-Platteville, 1 University Plaza , Platteville , Wisconsin 53818.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Frieders
authors.affiliation: d Department of Botany and Plant Pathology , Purdue University , West Lafayette , Indiana 47907.
authors.forename: M Catherine
authors.initials: MC
authors.lastname: Aime
mesh_terms: D001487:Basidiomycota / Q000254:growth & development* / Q000648:ultrastructure*; D025301:Hyphae / Q000254:growth & development* / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D008938:Mitosis
keywords: fungal evolution; hypha; microbody; mitosis; molecular phylogeny; septal pore; ultrastructure