Carole H. Sellem

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The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed sequence tag collection. Similar to higher eukaryotes, the P. anserina(More)
Among mobile genetic elements, self-splicing introns are of particular interest. They belong to either group I or group II depending on their three-dimensional structure. Homing, the systematic intron invasion of an intronless gene when it encounters its homologous intron-bearing allele, is the only means for intron mobility so far demonstrated. It depends(More)
We present here the properties of a complex III loss-of-function mutant of the filamentous fungus Podospora anserina. The mutation corresponds to a single substitution in the second intron of the gene cyc1 encoding cytochrome c(1), leading to a splicing defect. The cyc1-1 mutant is long-lived, exhibits a defect in ascospore pigmentation, has a reduced(More)
In Podospora anserina, inactivation of the respiratory chain results in a spectacular life-span extension. This inactivation is accompanied by the induction of the alternative oxidase. Although the functional value of this response is evident, the mechanism behind it is far from understood. By screening suppressors able to reduce the life-span extension of(More)
The mitochondrial chromosome of 15 Podo-spora anserina and one Podospora comata wild-type strains have been extensively examined for the presence of optional elements and for sequence divergence. Among the P. anserina strains, nine optional sequences were found. By comparing P. anserina with the closely related and weakly interfertile P. comata species, six(More)
In the filamentous fungus Podospora anserina, two nuclear genes are involved in the premature death syndrome associated with a site-specific deletion of the mitochondrial DNA: a mutant allele of the AS1 gene, encoding the cytoplasmic ribosomal protein S12, and an uncharacterized gene closely linked to the mating-type locus. We describe here the cloning and(More)
Senescence in Podospora anserina is always correlated with extrachromosomal mitochondrial DNA amplification (senDNA). Here we report a quantitative kinetic analysis of the molecular events that occur in the mitochondrial DNA of several wild-type cultures during aging. For each culture, the amplification of senDNA molecules and the modifications of the(More)
The mitochondrial genome of 23 wild-type strains belonging to three different species of the filamentous fungus Podospora was examined. Among the 15 optional sequences identified are two intronic reading frames, nad1-i4-orf1 and cox1-i7-orf2. We show that the presence of these sequences was strictly correlated with tightly clustered nucleotide substitutions(More)
Gene replacement via homologous recombination is a fundamental tool for the analysis of gene function. However, this event is rare in organisms like the filamentous fungus Podospora anserina. We show here that deletion of the PaKu70 gene is an efficient strategy for improving gene manipulation in this organism. By using the ΔPaKu70 strain, it is now(More)
Group II introns are widely distributed as attested by their recent discovery in several bacterial species (Ferat & Michel, 1993; Ferat, Le Gouar & Michel, 1994; Knoop & Brennicke, 1994). They are supposed to be relics of the RNA world and ancestors of the nuclear spliceosomal machinery (Cavalier-Smith, 1991; Sharp, 1991). Recent progress on their molecular(More)