Characterization of several NSD mutants of Aspergillus nidulans that never undergo sexual development

Several NSD (never in sexual development) mutants including one newly identified were characterized. None of cleistothecia were ever formed in standard conditions. NSD219 never developed any kind of sexual cells in any conditions. NSD204. NSD205 and NSD113 developed, however, normal cleistothecia on the minimal or complete media containing 3% glucose as C source. Growth of most mutants was retarded in compare with that of wild type. Asexual sporulation of the mutants occurred earlier than that of wild type. The nsdA, nsdB and nsdD loci were linked on linkage group II, V and VI, respectively. A novel NSD mutant, NSD113, belonged to the first group of the mutants which started to develop asexual spores just after release from aeration block. The mutant gene was complemented with nsdA4 and nsdB5 but mot nsdD19 indicating that it was an another allele of nsdD locus. The mutant allels was named as nsdD13 and was revealed to locate on linkage group VI.