title: Role of peg formation in clamp cell fusion of homobasidiomycete fungi.
abstract: In most filamentous basidiomycetes, clamp cells are found at the septa of dikaryotic mycelia. Clamp cell formation starts at hyphal tip cells with the development of a lateral bulge at a position slightly apical to the future septum. Relative to the growth direction of the hypha, the protrusion expands backwards into a hook-like structure. Next, the two genetically different haploid nuclei within the hyphal tip cell divide. A septum appears between clamp cell and hyphal tip cell, thereby trapping one nucleus within the clamp cell. Another septum is laid within the hypha, separating a nucleus of the other type in the newly generated subapical hyphal cell from the two different nuclei kept together in the new apical hyphal cell. Through fusion of clamp and subapical cell, the two solitary nuclei become united within the subapical hyphal compartment. In 1933, Buller described subapical formation of a peg to which the clamp cell fuses as an additional, subsequently neglected step in this series of events. In this study, we represent evidence for subapical peg formation and its role in clamp cell fusion. Our observations potentially indicate a B mating type regulated extracellular communication between clamp and subapical hyphal cell.
authors.affiliation: Yerevan State University, Department of Botany, 1 Aleg Manoogian Str., 375025, Yerevan, Armenia.
authors.forename: Suzanna M
authors.initials: SM
authors.lastname: Badalyan
authors.forename: Eline
authors.initials: E
authors.lastname: Polak
authors.forename: René
authors.initials: R
authors.lastname: Hermann
authors.forename: Markus
authors.initials: M
authors.lastname: Aebi
authors.forename: Ursula
authors.initials: U
authors.lastname: Kües
mesh_terms: D000363:Agaricales / Q000166:cytology* / Q000254:growth & development* / Q000648:ultrastructure; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D006238:Haploidy; D025301:Hyphae / Q000166:cytology* / Q000254:growth & development / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning