MSA - Systematics/Evolution
Healy, Rosanne , Kumar, T.K. Arun , McLaughlin, David J. .
Phylogenetic implications of septal pore ultrastructure in the basal Ascomycete Neolecta irregularis.
Molecular evidence from multiple genes place Neolecta in the Taphrinomycotina, a diverse assemblage of fungi that are basal to the Pezizomycotina and Saccharomycotina. Neolecta is remarkable because it is the only member of the Taphrinomycotina to produce a macroscopic fruiting body. Like Taphrina, it produces asci in a hymenium. These are the only two genera in the basal ascomycetes to have this derived character. As such, it is of great interest to know if the ascus and/or fruiting bodies of Neolecta and of the Pezizomycotina possess shared derived characters, or if these characters in Neolecta were independently derived. Septal pore ultrastructure, particularly in ascogenous and ascal septa, appear to be congruent with molecular phylogenies at family or higher levels. Our initial data indicate that the septal pores of mature Neolecta hyphae are uniperforate, and often partially or completely plugged with osmiophilic material. The appearance of this material in septal pores of interior filmentous hyphae of the ascocarp is similar to that of hymenial septal pores. The septal pore plugs of ascogenous and ascal hyphae are osmiophilic, span the pore, are inflated on either side of the pore (dumbbell-shaped), the surface of the plugs have a reticulate pattern, and the plugs are membrane bound. This pattern is unlike any of the various septal pore plugs reported in the Pezizomycotina. Crystalline bodies were observed in the pores with no accompanying osmiophilic plug material, as well as in the core of pore plugs of the interior filamentous hyphae. Crystalline bodies were not observed in our initial studies of ascogenous or ascal hyphal pores.
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1 - University of Minnesota, Department of Plant Biology, 250 Biological Sciences Center, 1445 Gortner Ave., St. Paul, MN, 55108, USA
Presentation Type: Poster:Posters for Topics
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM