Nuclear Behaviour and Spindle-pole Bodies During Ascosporogenesis in Peziza quelepidotia

SUMMARY The behaviour of nuclei and spindle-pole bodies in Peziza quelepidotia Korf & O'Donnell, a homothallic Discomycete, was investigated by light microscopy from ontogeny of the crozier up to ascosporogenesis. All nuclear divisions appeared to be intranuclear. Plaque-shaped spindle-pole bodies were discernible during the synchronous mitotic division in the crozier, the reductional division in the ascus and the mitotic division preceding sporogenesis. The intranuclear reductional division was of the 'Neurospora type' with no time interval between karyogamy and the onset of meiosis. This type of meiosis is further characterized by the presence of highly contracted homologues at synapsis and the absence of leptotene. A comparison of the behaviour of spindle-pole bodies in this species with other members of the Euascomycetidae is presented.