Journal of Microbiology

Research Support, Non-U.S. Gov't

NOTE] Isolation and Characterization of Self-Fertile Suppressors from the Sterile nsdD Deletion Mutant of Aspergillus nidulans: Dong-Beom Lee , Lee Han Kim , Jin-Pyo Kim , Kap-Hoon Han , Dong-Min Han; J. Microbiol. 2011;49(6):1054-1057. Published online December 28, 2011; DOI: https://doi.org/10.1007/s12275-011-1111-4

Abstract: To identify downstream and/or interactive factors of the nsdD gene, which encodes a positive regulator of sexual development of Aspergillus nidulans, suppressor mutants displaying a self-fertile phenotype were isolated from a sterile nsdD deletion mutant. At least five different loci (sndA-E) were identified and genetically analyzed. In the nsdD+ background, most of the suppressors showed a marked increment of sexual development, even under the stress conditions that normally inhibited sexual development. The common phenotype of the suppressor mutants suggested the involvement of the snd genes in the negative regulation of sexual development in response to the environmental factors.

Regulation of nsdD Expression in Aspergillus nidulans: Kap Hoon Han , Kyu-Yong Han , Min-Su Kim , Dong-Beom Lee , Jong-Hak Kim , Suhn-Kee Chae , Keon-Sang Chae , Dong-Min Han; J. Microbiol. 2003;41(3):259-261.

Abstract: The nsdD gene has been predicted to encode a GATA type transcription factor with the type IVb zinc finger DNA binding domain functions in activating sexual development of A. nidulans. In several allelic mutants of nsdD producing truncated NsdD polypeptides lacking the C-terminal zinc finger, the transcription level of nsdD gene was greatly increased. Also in an over-expressed mutant, the transcription under its own promoter was reduced. These results suggest that the expression of nsdD is negatively autoregulated. When the nsdD gene was over-expressed, cleistothecia were formed in excess amounts even in the presence of 0.6M KCl that inhibited sexual development of the wild type. Northern blot analysis revealed that the expression of nsdD was repressed by 0.6M KCl. These results strongly suggest that the inhibition of sexual development by salts was carried out via the nsdD involved regulatory network.

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