scholarly journals The impact of reproductive investment and early-life environmental conditions on senescence: support for the disposable soma hypothesis

2013 ◽  
Vol 26 (9) ◽  
pp. 1999-2007 ◽  
Author(s):  
M. Hammers ◽  
D. S. Richardson ◽  
T. Burke ◽  
J. Komdeur
2021 ◽  
Author(s):  
Janske van de Crommenacker ◽  
Martijn Hammers ◽  
Hannah Louise Dugdale ◽  
Terry Burke ◽  
Jan Komdeur ◽  
...  

1.Environmental conditions experienced during early life may have long-lasting effects on later-life phenotypes and fitness. Individuals experiencing poor early-life conditions may suffer subsequent fitness constraints. Alternatively, individuals may use a strategic ‘Predictive Adaptive Response’ (PAR), whereby they respond – in terms of physiology or life-history strategy – to the conditions experienced in early life to maximise later-life fitness. In particular, the Future Lifespan Expectation (FLE) PAR hypothesis predicts that when poor early-life conditions negatively impact an individual’s physiological state, individuals will accelerate their reproductive schedule to maximise fitness during their shorter predicted lifespan.2.We aimed to measure the impact of early-life conditions and resulting fitness across individual lifetimes to test the predictions of the FLE hypothesis in a wild, long-lived model species. 3.Using a long-term individual-based dataset, we investigated how early-life conditions are linked with subsequent fitness in an isolated population of the Seychelles warbler (Acrocephalus sechellensis). How individuals experience early-life environmental conditions may vary greatly, so we also tested whether telomere length – shorter telomers are a biomarker of an individual’s exposure to stress – can provide an effective measure of the individual-specific impact of early-life conditions. Specifically, under the FLE hypothesis, we would expect shorter telomeres to be associated with accelerated reproduction. 4.Contrary to expectations, shorter juvenile telomere length was not associated with poor early-life conditions, but instead with better conditions, probably as a result of faster juvenile growth. Furthermore, neither juvenile telomere length, nor other measures of early-life conditions, were associated with age of first reproduction or the rate of early-life reproduction in either sex. These results do not support the key prediction of the Future Lifetime Expectation PAR hypothesis. 5.We found no support for the FLE hypothesis. However, at least for males, poor early-life body conditions were associated with lower first year survival and reduced longevity, indicating that poor early-life conditions pose subsequent fitness constraints. Our results also showed that using juvenile telomere length as a measure of early-life conditions requires caution, as it is likely to not only reflect environmental stress but also other processes such as growth.


2020 ◽  
Author(s):  
Magdalena Wutkowska ◽  
Dorothee Ehrich ◽  
Sunil Mundra ◽  
Anna Vader ◽  
Pernille B. Eidesen

ABSTRACTArctic plants are affected by many stressors. Root-associated fungi are thought to influence plant performance in stressful environmental conditions. However, the relationships are not transparent; do the number of fungal partners, their ecological functions and community composition mediate the impact of environmental conditions and/or influence host plant performance? To address these questions, we used a common arctic plant as a model system: Bistorta vivipara. Whole plants (including root system) were collected from nine locations in Spitsbergen (n=214). Morphometric features were measured as a proxy for performance and combined with metabarcoding datasets of their root-associated fungi (amplicon sequence variants, ASVs), edaphic and meteorological variables. Seven biological hypotheses regarding fungal influence on plant measures were tested using structural equation modelling. The best-fitting model revealed that local temperature affected plants both directly (negatively aboveground and positively below-ground) and indirectly - mediated by fungal richness and the ratio of symbio- and saprotrophic ASVs. Fungal community composition did not impact plant measurements and plant reproductive investment did not depend on any fungal parameters. The lack of impact of fungal community composition on plant performance suggests that the functional importance of fungi is more important than their identity. The influence of temperature on host plants is therefore complex and should be examined further.


Author(s):  
Iman Alaie ◽  
Richard Ssegonja ◽  
Anna Philipson ◽  
Anne-Liis von Knorring ◽  
Margareta Möller ◽  
...  

Abstract Purpose Depression at all ages is recognized as a global public health concern, but less is known about the welfare burden following early-life depression. This study aimed to (1) estimate the magnitude of associations between depression in adolescence and social transfer payments in adulthood; and (2) address the impact of major comorbid psychopathology on these associations. Methods This is a longitudinal cohort study of 539 participants assessed at age 16–17 using structured diagnostic interviews. An ongoing 25-year follow-up linked the cohort (n = 321 depressed; n = 218 nondepressed) to nationwide population-based registries. Outcomes included consecutive annual data on social transfer payments due to unemployment, work disability, and public assistance, spanning from age 18 to 40. Parameter estimations used the generalized estimating equations approach. Results Adolescent depression was associated with all forms of social transfer payments. The estimated overall payment per person and year was 938 USD (95% CI 551–1326) over and above the amount received by nondepressed controls. Persistent depressive disorder was associated with higher recipiency across all outcomes, whereas the pattern of findings was less clear for subthreshold and episodic major depression. Moreover, depressed adolescents presenting with comorbid anxiety and disruptive behavior disorders evidenced particularly high recipiency, exceeding the nondepressed controls with an estimated 1753 USD (95% CI 887–2620). Conclusion Adolescent depression is associated with considerable public expenditures across early-to-middle adulthood, especially for those exposed to chronic/persistent depression and psychiatric comorbidities. This finding suggests that the clinical heterogeneity of early-life depression needs to be considered from a longer-term societal perspective.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1901
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.


2021 ◽  
Vol 22 (7) ◽  
pp. 3382
Author(s):  
Silvia Saturio ◽  
Alicja M. Nogacka ◽  
Marta Suárez ◽  
Nuria Fernández ◽  
Laura Mantecón ◽  
...  

The establishment of the gut microbiota poses implications for short and long-term health. Bifidobacterium is an important taxon in early life, being one of the most abundant genera in the infant intestinal microbiota and carrying out key functions for maintaining host-homeostasis. Recent metagenomic studies have shown that different factors, such as gestational age, delivery mode, or feeding habits, affect the gut microbiota establishment at high phylogenetic levels. However, their impact on the specific bifidobacterial populations is not yet well understood. Here we studied the impact of these factors on the different Bifidobacterium species and subspecies at both the quantitative and qualitative levels. Fecal samples were taken from 85 neonates at 2, 10, 30, 90 days of life, and the relative proportions of the different bifidobacterial populations were assessed by 16S rRNA–23S rRNA internal transcribed spacer (ITS) region sequencing. Absolute levels of the main species were determined by q-PCR. Our results showed that the bifidobacterial population establishment is affected by gestational age, delivery mode, and infant feeding, as it is evidenced by qualitative and quantitative changes. These data underline the need for understanding the impact of perinatal factors on the gut microbiota also at low taxonomic levels, especially in the case of relevant microbial populations such as Bifidobacterium. The data obtained provide indications for the selection of the species best suited for the development of bifidobacteria-based products for different groups of neonates and will help to develop rational strategies for favoring a healthy early microbiota development when this process is challenged.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cristian Carmeli ◽  
Zoltán Kutalik ◽  
Pashupati P. Mishra ◽  
Eleonora Porcu ◽  
Cyrille Delpierre ◽  
...  

AbstractIndividuals experiencing socioeconomic disadvantage in childhood have a higher rate of inflammation-related diseases decades later. Little is known about the mechanisms linking early life experiences to the functioning of the immune system in adulthood. To address this, we explore the relationship across social-to-biological layers of early life social exposures on levels of adulthood inflammation and the mediating role of gene regulatory mechanisms, epigenetic and transcriptomic profiling from blood, in 2,329 individuals from two European cohort studies. Consistently across both studies, we find transcriptional activity explains a substantive proportion (78% and 26%) of the estimated effect of early life disadvantaged social exposures on levels of adulthood inflammation. Furthermore, we show that mechanisms other than cis DNA methylation may regulate those transcriptional fingerprints. These results further our understanding of social-to-biological transitions by pinpointing the role of gene regulation that cannot fully be explained by differential cis DNA methylation.


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