Somatic Maintenance | ScienceGate

The relationship between brain size and ageing is a paradox. The cognitive benefits of large brains should protect from extrinsic mortality and thus indirectly select for slower ageing. However, the substantial energetic cost of neural tissue may also impact the energetic budget of large-brained organisms, causing less investment in somatic maintenance and thereby faster ageing. While the positive association between brain size and survival in the wild is well established, no studies exist on the direct effects of brain size on ageing. Here we test how brain size influences intrinsic ageing in guppy ( Poecilia reticulata ) brain size selection lines with 12% difference in relative brain size. Measuring survival under benign conditions, we find that large-brained animals live 22% shorter than small-brained animals and the effect is similar in both males and females. Our results suggest a trade-off between investment into brain size and somatic maintenance. This implies that the link between brain size and ageing is contingent on the mechanism of mortality, and selection for positive correlations between brain size and ageing should occur mainly under cognition-driven survival benefits from increased brain size. We show that accelerated ageing can be a cost of evolving a larger brain.

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Somatic Maintenance Resources in the Honeybee Worker Fat Body Are Distributed to Withstand the Most Life-Threatening Challenges at Each Life Stage

PLoS ONE ◽

10.1371/journal.pone.0069870 ◽

2013 ◽

Vol 8 (8) ◽

pp. e69870 ◽

Cited By ~ 13

Author(s):

Siri-Christine Seehuus ◽

Simon Taylor ◽

Kjell Petersen ◽

Randi M. Aamodt

Keyword(s):

Fat Body ◽

Life Stage ◽

Somatic Maintenance ◽

Honeybee Worker ◽

Life Threatening

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Nutrient allocation for somatic maintenance and worker production by the queen of the Japanese black carpenter ant, Camponotus japonicus (Hymenoptera: Formicidae)

Applied Entomology and Zoology ◽

10.1007/s13355-017-0505-0 ◽

2017 ◽

Vol 52 (3) ◽

pp. 527-530

Author(s):

Naoto Idogawa ◽

Mamoru Watanabe ◽

Tomoyuki Yokoi

Keyword(s):

Nutrient Allocation ◽

Somatic Maintenance ◽

Carpenter Ant ◽

Camponotus Japonicus

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Sex differences in senescence: the role of intra-sexual competition in early adulthood

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.1086 ◽

2015 ◽

Vol 282 (1811) ◽

pp. 20151086 ◽

Cited By ~ 32

Author(s):

Christopher Beirne ◽

Richard Delahay ◽

Andrew Young

Keyword(s):

Sex Differences ◽

Early Adulthood ◽

Meles Meles ◽

Reproductive Competition ◽

Sexual Competition ◽

Somatic Maintenance ◽

Downstream Effects ◽

Males And Females ◽

European Badgers

Males and females frequently differ in their rates of ageing, but the origins of these differences are poorly understood. Sex differences in senescence have been hypothesized to arise, because investment in intra-sexual reproductive competition entails costs to somatic maintenance, leaving the sex that experiences stronger reproductive competition showing higher rates of senescence. However, evidence that sex differences in senescence are attributable to downstream effects of the intensity of intra-sexual reproductive competition experienced during the lifetime remains elusive. Here, we show using a 35 year study of wild European badgers ( Meles meles ), that (i) males show higher body mass senescence rates than females and (ii) this sex difference is largely attributable to sex-specific downstream effects of the intensity of intra-sexual competition experienced during early adulthood . Our findings provide rare support for the view that somatic maintenance costs arising from intra-sexual competition can cause both individual variation and sex differences in senescence.

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Long-lived termite kings and queens activate telomerase in somatic organs

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.0511 ◽

2021 ◽

Vol 288 (1949) ◽

Author(s):

Justina Koubová ◽

Marie Pangrácová ◽

Marek Jankásek ◽

Ondřej Lukšan ◽

Tomáš Jehlík ◽

...

Keyword(s):

Catalytic Activity ◽

Similar Pattern ◽

Termite Species ◽

Eusocial Insects ◽

Somatic Maintenance ◽

Somatic Tissues ◽

Lifespan Regulation

Kings and queens of termites, like queens of other advanced eusocial insects, are endowed with admirable longevity, which dramatically exceeds the life expectancies of their non-reproducing nest-mates and related solitary insects. In the quest to find the mechanisms underlying the longevity of termite reproductives, we focused on somatic maintenance mediated by telomerase. This ribonucleoprotein is well established for pro-longevity functions in vertebrates, thanks primarily to its ability of telomere extension. However, its participation in lifespan regulation of insects, including the eusocial taxa, remains understudied. Here, we report a conspicuous increase of telomerase abundance and catalytic activity in the somatic organs of primary and secondary reproductives of the termite Prorhinotermes simplex and confirm a similar pattern in two other termite species. These observations stand in contrast with the telomerase downregulation characteristic for most adult somatic tissues in vertebrates and also in solitary insects and non-reproducing castes of termites. At the same time, we did not observe caste-specific differences in telomere lengths that might explain the differential longevity of termite castes. We conclude that although the telomerase activation in termite reproductives is in line with the broadly assumed association between telomerase and longevity, its direct phenotypic impact remains to be elucidated.

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Reproductive activation in honeybee ( Apis mellifera ) workers protects against abiotic and biotic stress

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0737 ◽

2021 ◽

Vol 376 (1823) ◽

pp. 20190737 ◽

Cited By ~ 1

Author(s):

Anissa Kennedy ◽

Jacob Herman ◽

Olav Rueppell

Keyword(s):

Oxidative Stress ◽

Social Insect ◽

Expression Patterns ◽

Cost Of Reproduction ◽

Physiological Level ◽

Exceptional Longevity ◽

Somatic Maintenance ◽

Whole Transcriptome Analysis ◽

Experimental Treatments ◽

Whole Transcriptome

Social insect reproductives exhibit exceptional longevity instead of the classic trade-off between somatic maintenance and reproduction. Even normally sterile workers experience a significant increase in life expectancy when they assume a reproductive role. The mechanisms that enable the positive relation between the antagonistic demands of reproduction and somatic maintenance are unclear. To isolate the effect of reproductive activation, honeybee workers were induced to activate their ovaries. These reproductively activated workers were compared to controls for survival and gene expression patterns after exposure to Israeli Acute Paralysis Virus or the oxidative stressor paraquat. Reproductive activation increased survival, indicating better immunity and oxidative stress resistance. After qPCR analysis confirmed our experimental treatments at the physiological level, whole transcriptome analysis revealed that paraquat treatment significantly changed the expression of 1277 genes in the control workers but only two genes in reproductively activated workers, indicating that reproductive activation preemptively protects against oxidative stress. Significant overlap between genes that were upregulated by reproductive activation and in response to paraquat included prominent members of signalling pathways and anti-oxidants known to affect ageing. Thus, while our results confirm a central role of vitellogenin, they also point to other mechanisms to explain the molecular basis of the lack of a cost of reproduction and the exceptional longevity of social insect reproductives. Thus, socially induced reproductive activation preemptively protects honeybee workers against stressors, explaining their longevity. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?'

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Allocation of pyloric caecum reserves in FED and starved sea stars, Pisaster giganteus (Stimpson): somatic maintenance comes before reproduction

Journal of Experimental Marine Biology and Ecology ◽

10.1016/0022-0981(80)90015-5 ◽

1980 ◽

Vol 48 (2) ◽

pp. 169-183 ◽

Cited By ~ 48

Author(s):

Christopher Harrold ◽

John S. Pearse

Keyword(s):

Pyloric Caecum ◽

Sea Stars ◽

Somatic Maintenance

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Evolution Under Dietary Restriction Decouples Survival From Fecundity in Drosophila melanogaster Females

The Journals of Gerontology Series A ◽

10.1093/gerona/gly070 ◽

2018 ◽

Vol 74 (10) ◽

pp. 1542-1548 ◽

Cited By ~ 13

Author(s):

Felix Zajitschek ◽

Grigorios Georgolopoulos ◽

Anna Vourlou ◽

Maja Ericsson ◽

Susanne R K Zajitschek ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Dietary Restriction ◽

Life History Theory ◽

Resource Reallocation ◽

Life Span Extension ◽

Somatic Maintenance ◽

Restriction Diet ◽

Investment In Reproduction ◽

The Cost ◽

Full Factorial

Abstract One of the key tenets of life-history theory is that reproduction and survival are linked and that they trade-off with each other. When dietary resources are limited, reduced reproduction with a concomitant increase in survival is commonly observed. It is often hypothesized that this dietary restriction effect results from strategically reduced investment in reproduction in favor of somatic maintenance to survive starvation periods until resources become plentiful again. We used experimental evolution to test this “waiting-for-the-good-times” hypothesis, which predicts that selection under sustained dietary restriction will favor increased investment in reproduction at the cost of survival because “good-times” never come. We assayed fecundity and survival of female Drosophila melanogaster fruit flies that had evolved for 50 generations on three different diets varying in protein content—low (classic dietary restriction diet), standard, and high—in a full-factorial design. High-diet females evolved overall increased fecundity but showed reduced survival on low and standard diets. Low-diet females evolved reduced survival on low diet without corresponding increase in reproduction. In general, there was little correspondence between the evolution of survival and fecundity across all dietary regimes. Our results contradict the hypothesis that resource reallocation between fecundity and somatic maintenance underpins life span extension under dietary restriction.

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