Meiosis in Aspergillus nidulans, Cytology of Wild Type and Mutants

Klaas Swart and Edu Holub.

Author address: 

Department of Genetics, Wageningen Agricultural University, Dreijenlaan 2, NL-6703 HA Wageningen, The Netherlands


The cytology of meiosis in Aspergillus nidulans was studied by haematoxylin staining and by acriflavin fluorescence. This study was undertaken to describe normal meiosis in this fungus and to characterise mutants blocked in meiosis. Such mutants are of' interest to identify and to clone genes that have a particular role in the progress of meiosis, either as differentiation genes or as genes involved in the process of recombination. The meiotic cells of A.nidulans are small compared to other well studied fungi like e.g. Neurospora crassa and Sordaria macrospora. The sequence of events in meiosis could clearly be established and appeared not to differ significantly from that described for other fungi. A uvsC mutant, defective in mitotic and meiotic recombination, was studied and was shown to be blocked at meiotic prophase 1. (Characterization of the uvsC gene revealed the homology to the yeast Rad5l gene, see poster by D. van Heemst et al). Specific meiotic mutants were isolated on basis of absence of mature ascospores in well developed cleistothecia (fruiting bodies). A meiA1 Mutant appeared to be blocked at anaphase 1. The cytology of wild type and mutant meiosis will be shown and discussed.

abstract No: 


Full conference title: 

    • ECFG 3rd (1996)