Characterization of a new fluffy mutant isolated by REMI in Aspergillus nidulans.

Gabriela Soid-Raegi, Olivia Sanchez, and Jesus Aguirre.


Aspergillus nidulans mutants showing delayed asexual sporulation (fluffy mutants) have been important to define signal transduction pathways needed for conidiation (Yu et al., 1996). A fluffy mutant named BLOW was isolated by REMI (Sanchez et al., 1998). The fluffy phenotype was shown to segregate as a monogenic mutation and to be linked to the argB marker used for REMI. Diploid complementation analysis and sexual crosses indicated that the mutation contained in BL001 is not allelic to other known fluffy genes. The affected gene in BL001 has been provisionally named fluX. Plasmid pREMI1, containing the vector used for REMI as well as flanking sequences, was recovered from mutant BL001. pREMI l insert was used to probe genomic DNA from wild type and fluffy strains derived from BL001. The hybridization patterns demonstrated that pREMI l contains genomic sequences from A. nidulans and that these are altered in the BL001 mutant and its offspring. However, cosmids identified using pREMIl insert failed to complement fluX1 phenotype. Sequence analysis of the insert showed that pREMIl is a chimerical plasmid likely produced during in vitro ligation. Nevertheless, sequences adjacent to the REMI insertion point should represent the actual genomic arrangement present in BL001. Sequence comparision of the identified cosmids and pREMII indicate that fluffy mutant BLOW contains a deletion. The fluX gene as well as other genes whose mutation causes fluffy phenotypes are required for conidiation induced by nitrogen starvation, but not for coniciation induced by glucose starvation.

abstract No: 

Fungal Genet. Newsl. 46 (Supl):

Full conference title: 

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