scholarly journals Does autophagy mediate age-dependent effect of dietary restriction responses in the filamentous fungus Podospora anserina ?

2014 ◽  
Vol 369 (1646) ◽  
pp. 20130447 ◽  
Author(s):  
Anne D. van Diepeningen ◽  
Daniël J. P. Engelmoer ◽  
Carole H. Sellem ◽  
Daphne H. E. W. Huberts ◽  
S. Marijke Slakhorst ◽  
...  

Autophagy is a well-conserved catabolic process, involving the degradation of a cell's own components through the lysosomal/vacuolar machinery. Autophagy is typically induced by nutrient starvation and has a role in nutrient recycling, cellular differentiation, degradation and programmed cell death. Another common response in eukaryotes is the extension of lifespan through dietary restriction (DR). We studied a link between DR and autophagy in the filamentous fungus Podospora anserina , a multicellular model organism for ageing studies and mitochondrial deterioration. While both carbon and nitrogen restriction extends lifespan in P. anserina, the size of the effect varied with the amount and type of restricted nutrient. Natural genetic variation for the DR response exists. Whereas a switch to carbon restriction up to halfway through the lifetime resulted in extreme lifespan extension for wild-type P. anserina , all autophagy-deficient strains had a shorter time window in which ageing could be delayed by DR. Under nitrogen limitation, only Pa Atg1 and Pa Atg8 mediate the effect of lifespan extension; the other autophagy-deficient mutants Pa PspA and Pa Uth1 had a similar response as wild-type. Our results thus show that the ageing process impinges on the DR response and that this at least in part involves the genetic regulation of autophagy.

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Koumei Yazaki ◽  
Chinatsu Yoshikoshi ◽  
Satoru Oshiro ◽  
Sumino Yanase

Astaxanthin (AX), which is produced by some marine animals, is a type of carotenoid that has antioxidative properties. In this study, we initially examined the effects of AX on the aging of a model organismC. elegansthat has the conserved intracellular pathways related to mammalian longevity. The continuous treatments with AX (0.1 to 1 mM) from both the prereproductive and young adult stages extended the mean lifespans by about 16–30% in the wild-type and long-lived mutantage-1ofC. elegans. In contrast, the AX-dependent lifespan extension was not observed even in adaf-16null mutant. Especially, the expression of genes encoding superoxide dismutases and catalases increased in two weeks after hatching, and the DAF-16 protein was translocated to the nucleus in the AX-exposed wild type. These results suggest that AX protects the cell organelle mitochondria and nucleus of the nematode, resulting in a lifespan extension via an Ins/IGF-1 signaling pathway during normal aging, at least in part.


MycoKeys ◽  
2020 ◽  
Vol 75 ◽  
pp. 51-69
Author(s):  
S. Lorena Ament-Velásquez ◽  
Hanna Johannesson ◽  
Tatiana Giraud ◽  
Robert Debuchy ◽  
Sven J. Saupe ◽  
...  

The filamentous fungus Podospora anserina has been used as a model organism for more than 100 years and has proved to be an invaluable resource in numerous areas of research. Throughout this period, P. anserina has been embroiled in a number of taxonomic controversies regarding the proper name under which it should be called. The most recent taxonomic treatment proposed to change the name of this important species to Triangularia anserina. The results of past name changes of this species indicate that the broader research community is unlikely to accept this change, which will lead to nomenclatural instability and confusion in literature. Here, we review the phylogeny of the species closely related to P. anserina and provide evidence that currently available marker information is insufficient to resolve the relationships amongst many of the lineages. We argue that it is not only premature to propose a new name for P. anserina based on current data, but also that every effort should be made to retain P. anserina as the current name to ensure stability and to minimise confusion in scientific literature. Therefore, we synonymise Triangularia with Podospora and suggest that either the type species of Podospora be moved to P. anserina from P. fimiseda or that all species within the Podosporaceae be placed in the genus Podospora.


Author(s):  
Laura M. Travers ◽  
Hanne Carlsson ◽  
Elizabeth M. L. Duxbury ◽  
Alexei A. Maklakov

AbstractDietary restriction (DR), reduced food intake without malnutrition, increases lifespan across a broad range of taxa, but the evolutionary underpinning of this phenomenon is poorly understood. The resource reallocation hypothesis proposes that dietary restricted animals divert resources from reproduction to somatic maintenance to increase survival in times of nutrient scarcity in favour of future reproduction. The “longevity by-product” hypothesis proposes instead that dietary restricted animals increase nutrient recycling via autophagy to maximise immediate reproduction, thereby reducing cellular toxic waste and leading to longer lifespan as an unselected by-product. The “longevity by-product” hypothesis makes a unique prediction that blocking autophagy in DR animals will simultaneously reduce lifespan and reproduction. To test the adaptive value of autophagy under dietary restriction, we inhibited autophagy using bec-1 RNAi knockdown in DR and fully-fed Caenorhabditis elegans nematodes. Our findings confirm that autophagic inhibition results in a significantly shorter lifespan under DR, suggesting that autophagy is important for survival in times of famine. Remarkably, we also show that inhibiting autophagy throughout adult life significantly increases reproduction in both dietary restricted and fully fed worms. Moreover, this did not come at a transgenerational cost to offspring fitness. Our results suggest that autophagy is an energetically costly process that reduces resources available for reproduction, but is necessary for survival during famine, and are thus consistent with the resource reallocation hypothesis.


2021 ◽  
Vol 13 ◽  
Author(s):  
Abdullah Almotayri ◽  
Jency Thomas ◽  
Mihiri Munasinghe ◽  
Markandeya Jois

Background: The antidepressant mianserin has been shown to extend the lifespan of Caenorhabditis elegans (C. elegans), a well-established model organism used in aging research. The extension of lifespan in C. elegans was shown to be dependent on increased expression of the scaffolding protein (ANK3/unc-44). In contrast, antidepressant use in humans is associated with an increased risk of death. The C. elegans in the laboratory are fed Escherichia coli (E. coli), a diet high in protein and low in carbohydrate, whereas a typical human diet is high in carbohydrates. We hypothesized that dietary carbohydrates might mitigate the lifespan-extension effect of mianserin. Objective: To investigate the effect of glucose added to the diet of C. elegans on the lifespan-extension effect of mianserin. Methods: Wild-type Bristol N2 and ANK3/unc-44 inactivating mutants were cultured on agar plates containing nematode growth medium and fed E. coli. Treatment groups included (C) control, (M50) 50 μM mianserin, (G) 73 mM glucose, and (M50G) 50 μM mianserin and 73 mM glucose. Lifespan was determined by monitoring the worms until they died. Statistical analysis was performed using the Kaplan-Meier version of the log-rank test. Results: Mianserin treatment resulted in a 12% increase in lifespan (P<0.05) of wild-type Bristol N2 worms but reduced lifespan by 6% in ANK3/unc-44 mutants, consistent with previous research. The addition of glucose to the diet reduced the lifespan of both strains of worms and abolished the lifespan-extension by mianserin. Conclusion: The addition of glucose to the diet of C. elegans abolishes the lifespan-extension effects of mianserin.


Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 71-81
Author(s):  
Eric Espagne ◽  
Pascale Balhadère ◽  
Marie-Louise Penin ◽  
Christian Barreau ◽  
Béatrice Turcq

Abstract Vegetative incompatibility, which is very common in filamentous fungi, prevents a viable heterokaryotic cell from being formed by the fusion of filaments from two different wild-type strains. Such incompatibility is always the consequence of at least one genetic difference in specific genes (het genes). In Podospora anserina, alleles of the het-e and het-d loci control heterokaryon viability through genetic interactions with alleles of the unlinked het-c locus. The het-d2Y gene was isolated and shown to have strong similarity with the previously described het-e1A gene. Like the HET-E protein, the HET-D putative protein displayed a GTP-binding domain and seemed to require a minimal number of 11 WD40 repeats to be active in incompatibility. Apart from incompatibility specificity, no other function could be identified by disrupting the het-d gene. Sequence comparison of different het-e alleles suggested that het-e specificity is determined by the sequence of the WD40 repeat domain. In particular, the amino acids present on the upper face of the predicted β-propeller structure defined by this domain may confer the incompatible interaction specificity.


2021 ◽  
pp. 074873042199811
Author(s):  
Franziska Ruf ◽  
Oliver Mitesser ◽  
Simon Tii Mungwa ◽  
Melanie Horn ◽  
Dirk Rieger ◽  
...  

The adaptive significance of adjusting behavioral activities to the right time of the day seems obvious. Laboratory studies implicated an important role of circadian clocks in behavioral timing and rhythmicity. Yet, recent studies on clock-mutant animals questioned this importance under more naturalistic settings, as various clock mutants showed nearly normal diel activity rhythms under seminatural zeitgeber conditions. We here report evidence that proper timing of eclosion, a vital behavior of the fruit fly Drosophila melanogaster, requires a functional molecular clock under quasi-natural conditions. In contrast to wild-type flies, period01 mutants with a defective molecular clock showed impaired rhythmicity and gating in a temperate environment even in the presence of a full complement of abiotic zeitgebers. Although period01 mutants still eclosed during a certain time window during the day, this time window was much broader and loosely defined, and rhythmicity was lower or lost as classified by various statistical measures. Moreover, peak eclosion time became more susceptible to variable day-to-day changes of light. In contrast, flies with impaired peptidergic interclock signaling ( Pdf01 and han5304 PDF receptor mutants) eclosed mostly rhythmically with normal gate sizes, similar to wild-type controls. Our results suggest that the presence of natural zeitgebers is not sufficient, and a functional molecular clock is required to induce stable temporal eclosion patterns in flies under temperate conditions with considerable day-to-day variation in light intensity and temperature. Temperate zeitgebers are, however, sufficient to functionally rescue a loss of PDF-mediated clock-internal and -output signaling


Aging Cell ◽  
2010 ◽  
Vol 10 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Laurent Mouchiroud ◽  
Laurent Molin ◽  
Prasad Kasturi ◽  
Mohamed N. Triba ◽  
Marc Emmanuel Dumas ◽  
...  

1999 ◽  
Vol 19 (6) ◽  
pp. 4093-4100 ◽  
Author(s):  
Odile Begel ◽  
Jocelyne Boulay ◽  
Beatrice Albert ◽  
Eric Dufour ◽  
Annie Sainsard-Chanet

ABSTRACT 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 (α) has been thought to play a prominent role in this syndrome. Intron α 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 theCOX1 gene. We describe here the first mutant of P. anserina that has the α 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 α. 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 α is not the specific senescence factor but rather an accelerator or amplifier of the senescence process. They emphasize the role that intron α 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 α but rather by the lack of active cytochromec oxidase.


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