Genetic Control of Aging in the Ascomycete Podospora anserina

Osiewacz, H. D.

doi:10.1007/978-3-642-85789-8_16

Cited by 11 publications

(4 citation statements)

References 40 publications

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“…The role of this intron in the senescence process of P. anserina has been a much-debated question. On one hand, it has been hypothesized that the senDNAs (20), and especially senDNA ␣ (5,14,30), correspond to the senescence factor that Marcou (25) called the determinant. On the other hand, it has been speculated that senDNA ␣ and the other senDNAs have only a secondary role in the senescence process (47).…”

Section: Discussionmentioning

confidence: 99%

Mitochondrial Group II Introns, Cytochrome c Oxidase, and Senescence in Podospora anserina

Begel

Boulay

Albert

et al. 1999

Molecular and Cellular Biology

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Podospora anserina is a filamentous fungus with a limited life span. It expresses a degenerative syndrome called senescence, which is always associated with the accumulation of circular molecules (senDNAs) containing specific regions of the mitochondrial chromosome. A mobile group II intron (alpha) has been thought to play a prominent role in this syndrome. Intron alpha is the first intron of the cytochrome c oxidase subunit I gene (COX1). Mitochondrial mutants that escape the senescence process are missing this intron, as well as the first exon of the COX1 gene. We describe here the first mutant of P. anserina that has the alpha sequence precisely deleted and whose cytochrome c oxidase activity is identical to that of wild-type cells. The integration site of the intron is slightly modified, and this change prevents efficient homing of intron alpha. We show here that this mutant displays a senescence syndrome similar to that of the wild type and that its life span is increased about twofold. The introduction of a related group II intron into the mitochondrial genome of the mutant does not restore the wild-type life span. These data clearly demonstrate that intron alpha is not the specific senescence factor but rather an accelerator or amplifier of the senescence process. They emphasize the role that intron alpha plays in the instability of the mitochondrial chromosome and the link between this instability and longevity. Our results strongly support the idea that in Podospora, "immortality" can be acquired not by the absence of intron alpha but rather by the lack of active cytochrome c oxidase.

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Section: Discussionmentioning

confidence: 99%

Mitochondrial Group II Introns, Cytochrome c Oxidase, and Senescence in Podospora anserina

Begel

Boulay

Albert

et al. 1999

Molecular and Cellular Biology

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“…Based on their structure and replicative properties, two classes of senDNAs can be defined: (1) senDNA␣ corresponds exactly to the first intron of the mitochondrially encoded cox1 gene or intron ␣ (Osiewacz and Esser, 1984). Intron ␣ is present in all wild-type races (Kü ck et al, 1985) and senDNA␣ almost systematically appears during senescence (Dujon and Belcour, 1989;Osiewacz, 1992). It does not accumulate by autoreplication but most likely by a retrotransposition mechanism (Jamet-Vierny et al, 1997a;Sainsard-Chanet et al, 1994).…”

Section: Academic Pressmentioning

confidence: 99%

What Triggers Senescence in Podospora anserina?

Jamet‐Vierny

Rossignol

Haedens

et al. 1999

Fungal Genetics and Biology

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“…Integration of the liberated plasmids into the nuclear genome, or homologous recombination between the plasmids and mtDNA, can lead to inactivation of essential nuclear and mitochondrial genes (e.g. the cytochrome c oxidase gene), causing disintegration of mtDNA and thus apparently contributing to the onset of senescence (Wright & Cummings, 1983 ;Esser, 1985 ;Osiewacz, 1990Osiewacz, , 1992. On the other hand, overproduction of proteins coded by the amplified plasmids can contribute to the induction of mtDNA rearrangements (Belcour et al, 1981 ;Schulte et al, 1988).…”

Section: Te-associated Aging In Fungimentioning

confidence: 99%