Martinez-Rossi N M, Azevedo J L
Mutat Res. 1982 Sep;96(1):31-9. doi: 10.1016/0027-5107(82)90014-8.
5 mutants of Aspergillus nidulans, selected for resistance to chloroneb, were also partially dependent on it. The resistance of these mutants to chloroneb was about 20-150 times higher than that of the original strain. The resistance marker was due to a mutation in a single gene, located in linkage group III, and behaved as a recessive character. This genetic marker was distal in relation to galAl with a recombination frequency of about 30-35%. The different levels of resistance were attributed to mutations at different sites in the same locus. Both stable and unstable sectors were obtained from resistant strains inoculated on chloroneb-free medium. The emergence of stable sectors was due to back mutation, suppressor mutation or another mutation, which allows growth to the full extent in the absence of the drug. The unstable sectors showed better growth when compared with the resistant strain, kept their resistance and produced both resistant and non-resistant secondary sectors. This procedure of 2-way selection of mutants and revertants to chloroneb resistance could be useful for studying forward and back mutation in A. nidulans.
5株经氯苯灵抗性筛选的构巢曲霉突变体也部分依赖于氯苯灵。这些突变体对氯苯灵的抗性比原始菌株高约20 - 150倍。抗性标记是由位于Ⅲ连锁群的单个基因突变引起的，表现为隐性性状。该遗传标记相对于galAl位于远端，重组频率约为30 - 35%。不同水平的抗性归因于同一基因座不同位点的突变。从接种在不含氯苯灵培养基上的抗性菌株中获得了稳定和不稳定的扇形菌落。稳定扇形菌落的出现是由于回复突变、抑制突变或另一种突变，使得在没有药物的情况下能够充分生长。与抗性菌株相比，不稳定扇形菌落生长更好，保持其抗性，并产生抗性和非抗性的次级扇形菌落。这种双向筛选氯苯灵抗性突变体和回复体的方法可能有助于研究构巢曲霉中的正向和反向突变。
