The fle1 gene encoding a C2H2 zinc finger protein co-ordinates male and female sexual differentiation in Podospora anserina.
The flexuosa (fle1-1) mutant, isolated in Podospora anserina, displays vegetative defects and two antagonistic sexual phenotypes: it produces several 1000-fold fewer microconidia (male gametes) than the wild-type strain and, conversely, more abundant protoperithecia (female organs). Cloning and sequencing of the fle1 gene and of cDNA identified an open reading frame encoding a 382-amino-acid polypeptide with two C2H2 zinc finger motifs. The predicted FLE1 protein shares 46% identity with the FlbC protein of Aspergillus nidulans and 68% identity with a putative protein identified by a search in the Neurospora crassa database. The nuclear localization of FLE1 was demonstrated by fusion with the green fluorescent protein. Sequencing of the fle1-1 mutant allele revealed a frameshift mutation upstream of the zinc finger domain. The fle1-1 mutant was a null mutant, as targeted disruption of fle1 sequence led to the same pleiotropic phenotype. When fle1 was overexpressed by introduction of a transgenic copy of the native fle1 gene or a fusion with a strong promoter, formation of protoperithecia was impaired, leading to partial or complete female sterility. We propose that fle1 acts as a repressor of female sexual differentiation in order to maintain the balance between male and female sexual pathways.
Coppin
Evelyne
E
Institut de Génétique et Microbiologie, UMR 8621 CNRS-Université Paris Sud, Bâtiment 400, 91405 Orsay cedex, France. coppin@igmors.u-psud.fr
D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012733:Sex Differentiation / Q000235:genetics*; D020037:Sordariales / Q000235:genetics / Q000502:physiology*; D019076:Transgenes; D016335:Zinc Fingers / Q000235:genetics*
D002352:Carrier Proteins; D005656:Fungal Proteins; D008164:Luminescent Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins