Identification of an upstream gene that affects aflR expression.

Yitine Huane, and Jae-Hyuk Yu.


A mutant hunt was conducted to identify and isolate genes which regulate the gene activator, af1R, in the sterigmatocystin (ST) / aflatoxin gene cluster in certain Aspergillus species. aflR resides within the ST gene cluster and is known to regulate the expression of all other genes within the cluster. A special mutant strain of A. nidulans, LY345, carrying multiple copies of the ST gene cluster, was mutagenized with 4-nitroquinoline-l-oxide. Mutants were screened for the production of ST intermediates. A mutant of LY345, YH7239, was unable to produce any ST intermediates. Northern analysis showed this strain produces no af1R transcript. Since all ST cluster genes in LY345 are buffered against mutations within the gene cluster by virtue of multiple copies, the mutant, YH7239, is presumed to carry a mutation in a possible regulatory gene located external to ST gene cluster. Future work will be directed at rescue and cloning of this presumptive regulatory gene.

abstract No: 

Fungal Genet. Newsl. 46 (Supl):

Full conference title: 

Fungal Genetics Conference 20th
    • Fungal Genetics Conference 20th (1999)