Multiple copies of the amdS gene of Aspergillus nidulans cause titration of trans-acting regulatory proteins
Date
1987
Authors
Kelly, J.M.
Hynes, M.J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Current Genetics: lower eukaryotes and organelles, 1987; 12(1):21-31
Statement of Responsibility
Joan M. Kelly and M. J. Hynes
Conference Name
Abstract
It has been established that a plasmid containing the amdS gene of Aspergillus nidulans may be used to transform amdS+ strains by selecting for increased utilization of acetamide as sole nitrogen source. Analysis of transformants has shown that multiple tandem copies of the plasmid can be integrated into the chromosome, commonly at sites other than the amdS locus. While the transformed phenotype was relatively stable through mitotic and meiotic divisions evidence was found for variation in plasmid copy number presumably due to unequal recombination events. Expression of the integrated amdS genes was related to copy number, and the amdS RNA produced was similar in size to wild-type RNA. Evidence for titration of the product of the regulatory gene amdR by multiple copies of amdS was found. No titration of the product of the areA gene was observed, and amdS expression was still dependent on areA function. Multiple copies of the amdI9 mutation resulted in poor growth on acetate. This was not observed in the case of the amdS+ gene. The cis-acting amdI9 mutation causes increased facB dependent acetate induction of amdS expression. Titration of the facB gene produce by amdI9 DNA, but not by amdS+ DNA, therefore suggested that the mutation results in increased affinity for the facB gene product.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© Springer-Verlag 1987