Maternal age effects on offspring lifespan and reproduction vary within a species (original) (raw)

Maternal age alters offspring lifespan, fitness, and lifespan extension under caloric restriction

2019

ABSTRACTMaternal age has a negative effect on offspring lifespan in a range of taxa and is hypothesized to influence the evolution of aging. However, the mechanisms of maternal age effects are unknown, and it remains unclear if maternal age alters offspring response to therapeutic interventions to aging. Here, we evaluate maternal age effects on offspring lifespan, reproduction, and the response to caloric restriction, and investigate maternal investment as a source of maternal age effects using the rotifer,Brachionus manjavacas, an aquatic invertebrate. We found that offspring lifespan and fecundity decline with increasing maternal age. Caloric restriction increases lifespan in all offspring, but the magnitude of lifespan extension is greater in the offspring from older mothers. The trade-off between reproduction and lifespan extension under low food conditions expected by life history theory is observed in young-mother offspring, but not in old-mother offspring. Age-related change...

Measurement of Survival Time in <em>Brachionus </em>Rotifers: Synchronization of Maternal Conditions

Journal of Visualized Experiments, 2016

Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

Diversity of ageing across the tree of life

Nature, 2014

phenotype's age-patterns of mortality and fertility in an environment; these two 2 patterns in turn determine the genotype's fitness in that environment. Hence, to 3 understand the evolution of ageing, age-patterns of mortality and reproduction 4 need to be compared for species across the tree of life. Yet no study has done so. 5

Life history response and age-specific tolerance to starvation in Brachionus plicatilis O.F. Müller (Rotifera)

Journal of Experimental Marine Biology and Ecology, 2003

To examine the life history response and age-specific tolerance to starvation in the rotifer Brachionus plicatilis O.F. Müller, we carried out two series of individual culture experiments. In the first experiment, rotifers were fed until each of the ages of 1-4 days, and were then starved during the rest of their lifetimes. The control group was fed throughout their lifespans. Rotifers stopped active reproduction just after the onset of food deprivation, and showed shorter subsequent survival times when they were starved at older ages. The finding that the larger the number of offspring produced before food deprivation, the shorter the subsequent lifetime under starvation, appeared to reflect a trade-off with the cost of reproduction. In the second experiment, newborns were starved until each of the ages of 1-5 days, and were fed thereafter. The lifespans of the rotifers starved up to the age of 3 days were not statistically different from those that were not starved. Although the starved rotifers began to reproduce once fed again, their lifetime fecundity decreased significantly from that of the non-starved group. Based on these results, it was suggested that the reproductive suppression caused by starvation would cause rotifers to have a longer lifespan to allow for future reproduction.

Maternal age and spine development in a rotifer: ecological implications and evolution

Ecology, 2013

Brachionus calyciflorus typically develops long, defensive spines only in response to a kairomone from the predatory rotifer, Asplanchna. However, in the absence of any environmental induction, females of some clones produce daughters with increasingly long spines as they age; late-born individuals can have posterolateral spines as long as those induced by Asplanchna: up to 50% or more of body length. Here, we construct a model using data from life-table and predator-prey experiments to assess how this maternal-age effect can influence the distribution of spine lengths in reproducing populations and provide defense against Asplanchna predation. When Asplanchna is absent, the frequency of individuals with late birth orders rapidly becomes extremely low; thus, any cost associated with the production of long-spined individuals is minimal. When Asplanchna is present at densities too low for spine induction, and preys selectively on individuals with no or short posterolateral spines, the frequency of long-spined individuals rapidly increases until a stable birth-order structure is reached. As a result, mortality from Asplanchna predation is greatly reduced. The pronounced and novel birth-order effect in this rotifer appears to be an effective bet-hedging strategy to limit predation by Asplanchna when its kairomone induces no or less than maximal spine development.

A demographic and evolutionary analysis of maternal effect senescence

Proceedings of the National Academy of Sciences, 2020

SignificanceMaternal effect senescence, the decline in offspring quality with increasing maternal age, is common in animals despite its negative impact on fitness. To understand how maternal effect senescence might evolve, we built matrix population models to calculate selection gradients on survival and fertility as functions of maternal age. We estimated the model’s parameters with data from an aquatic invertebrate. The strength of selection eventually declines with age and maternal age, implying that maternal effect senescence could be favored by selection and evolve in the same way as senescence. Our framework can be applied to investigate maternal effect senescence in organisms with diverse life histories and unifies the demographic approaches to age-related and maternal effect senescence.

Genome-wide transcriptomics of aging in the rotifer Brachionus manjavacas, an emerging model system

BMC genomics, 2017

Understanding gene expression changes over lifespan in diverse animal species will lead to insights to conserved processes in the biology of aging and allow development of interventions to improve health. Rotifers are small aquatic invertebrates that have been used in aging studies for nearly 100 years and are now re-emerging as a modern model system. To provide a baseline to evaluate genetic responses to interventions that change health throughout lifespan and a framework for new hypotheses about the molecular genetic mechanisms of aging, we examined the transcriptome of an asexual female lineage of the rotifer Brachionus manjavacas at five life stages: eggs, neonates, and early-, late-, and post-reproductive adults. There are widespread shifts in gene expression over the lifespan of B. manjavacas; the largest change occurs between neonates and early reproductive adults and is characterized by down-regulation of developmental genes and up-regulation of genes involved in reproductio...

Parent age, lifespan and offspring survival: structured variation in life history in a wild population

Journal of Animal Ecology, 2010

1. Understanding the degree to which reproductive success varies with an individual's age and lifespan, and the degree to which population-level variation mirrors individual-level variation, is central to understanding life-history evolution and the dynamics of age-structured populations. We quantified variation in the survival probability of offspring, one key component of reproductive success and fitness, in relation to parent age and lifespan in a wild population of red-billed choughs (Pyrrhocorax pyrrhocorax). 2. On average across the study population, the first-year survival probability of offspring decreased with increasing parent age and lifespan; offspring of old parents were less likely to survive than offspring of young parents, and offspring of long-lived parents were less likely to survive than offspring of short-lived parents. 3. However, survival did not vary with parent age across offspring produced by groups of parents that ultimately had similar lifespans. 4. Rather, across offspring produced by young parents, offspring survival decreased with increasing parent lifespan; parents that ultimately had long lifespans produced offspring that survived poorly, even when these parents were breeding at young ages. 5. The average decrease in offspring survival with increasing parent age observed across the population therefore reflected the gradual disappearance of short-lived parents that produced offspring that survived well, not age-specific variation in offspring survival within individual parents. 6. The negative correlation between offspring survival and maternal lifespan was strongest when environmental conditions meant that offspring survival was low across the population. 7. These data suggest an environment-dependent trade-off between parent and offspring survival, show consistent individual variation in the resolution of this trade-off that is set early in a parent's life, and demonstrate that such structured life-history variation can generate spurious evidence of senescence in key fitness components when measured across a population.

Effect of Population-Density and Genotype on Life-History Traits in the Rotifer Brachionus-Plicatilis MULLER,O.F

Journal of Experimental Marine Biology and Ecology

Effects of population density on mictic response and the population dynamics of 13 clones of Bruchionus plicatilis were investigated by culturing isolated females at two different population densities. Results from the experiments did not provide general support for the dependence of mictic response on population density. Only six clones, isolated amictic females cultured at a density of 5 females*ml-', produced higher proportions of mictic female offspring than females grown at a density of 1 female.ml-', indicating that mictic-female production in these clones of B. plicatilis is density-dependent. High population density affected other life-history traits: lifespan (e,) and fertility per female lifetime (R,) decreased with density. Interclone differences in the mictic response to density were detected, which may be caused by genetic differences in the capacity to undergo mixis. High variabilities for mictic rates and life-table parameters were found among clones derived by selting from a clone. These results indicate that age of the parental female is also a signiticant internal factor that affects the production of mictic daughters.