Variation In Lifespan Research Articles

Spatial and Temporal Variation in the Life‐History Traits of Yellow Perch (Perca flavescens) in the Canadian Waters of Lake Huron

ABSTRACTThe yellow perch (Perca flavescens) is an economically important fish species in the Laurentian Great Lakes of North America. The largest commercial harvests occur in Lakes Erie and Huron. In the Canadian waters of Lake Huron, the yellow perch is managed based on 17 spatially distinct management units established decades ago. Despite being the basis for commercial harvest quotas, it is unknown if management units reflect current yellow perch population structure, or if yellow perch life‐history traits changed following a major ecosystem shift associated with invasive mussels in the early 2000s. We calculated life‐history trait parameter values (size at maturity, age at maturity, maximum size, lifespan and growth rate) for female yellow perch across the Canadian portion of Lake Huron in recent (2009–2018, 9264 fish) and historical (1990–1999, 3540 fish) timeframes. We spatially compared recent life‐history trait values and found four discrete clusters of yellow perch driven by latitudinal variation in age at maturity and maximum size, and longitudinal variation in maximum size and lifespan. The depth of capture was an important influence on yellow perch growth rate. We compared recent and historical life‐history trait values and found no temporal variation before and after dreissenid mussel invasion. Our findings demonstrate significant spatial variation in yellow perch life‐history traits but, over spatial scales, much larger than the current management units. Correspondingly, life‐history trait values alone are likely not sufficient for understanding population subdivision in the Canadian waters of Lake Huron.

Analysis of lifespan across Diversity Outbred mouse studies identifies multiple longevity-associated loci.

Lifespan is an integrative phenotype whose genetic architecture is likely to highlight multiple processes with high impact on health and aging. Here, we conducted a genetic mega-analysis of longevity in Diversity Outbred (DO) mice that included 2,444 animals from three independently conducted lifespan studies. We identified eight loci that contributed significantly to lifespan independently of diet and drug treatment in at least one study. One of these loci also influenced lifespan in a sex-dependent manner, and we detected an additional locus with a diet-specific effect on lifespan. Collectively, these loci explained over half of the estimated heritable variation in lifespan across these studies and provided insight into the genetic architecture of lifespan in DO mice.

Honey bee (Apis mellifera) queen quality: host-microbial transcriptomes exploring the influence of age and hindgut symbiont Commensalibacter melissae

Understanding the biological mechanisms underlying extreme lifespan variation within species remains a fundamental challenge in aging research. Here, we investigated the role of gut microbiota and age in honey bee (Apis mellifera) queens combining 16S rRNA gene sequencing and transcriptomics. Analysis of 40 queen hindguts revealed that Commensalibacter melissae (Alpha 2.1) relative abundance was significantly higher in young queens compared to old queens. Using queens with the highest and lowest C. melissae relative abundance, RNA sequencing identified 1451 differentially expressed genes associated with C. melissae abundance, twice the number associated with age alone (719 genes). Queens with high C. melissae abundance showed distinct transcriptional profiles related to stress response, protein homeostasis, and longevity-regulating pathways, particularly genes involved in oxidative stress response and cellular maintenance. Our analysis revealed complex relationships between age, C. melissae abundance, and gene expression patterns, suggesting that multiple interacting factors contribute to queen quality. These findings contribute to our understanding of host-microbe interactions in honey bee queens and highlight the intricate relationship between gut microbiota composition and host physiology in honey bees.

Aging patterns and predicting longevity from early-life performance in a solitary bee

Performance, including muscle function and stress tolerance, tends to decline with age. However, there is considerable variation in performance among individuals of the same age, highlighting that chronological age does not always reflect biological age. To better understand the mechanisms behind aging, it is crucial to identify what drives some individuals to age more rapidly than others. However, we must first be able to predict whether an individual will have a long or short lifespan. Here we conducted a longitudinal study to explore how locomotor activity, cold tolerance (chill-coma recovery time), and resting metabolic rates change with age using the solitary bee Megachile rotundata. After determining how each performance changes with age, we assessed whether short-lived individuals performance differed from long-lived individuals during early-life. Results show that locomotor activity and chill-coma recovery time decline with age, and resting metabolic rates remain stable throughout their lifespan. During early-life, low cold tolerance and low mass at emergence are linked to shorter lifespans, but only in female bees. These findings indicate that an individual’s early-life performance account for some of the variation in lifespans seen within a population. Additionally, the results contribute to the growing evidence that not all traits decline with age, and show strong sex-specific aging patterns for all three physiological traits measured. This work was funded by NSF-IOS-2311952, USDA-ARS 3060-21220-032-00D, and USDA-ARS NACA 58-3060-3-023. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Rectify the impact of shorter red blood cell lifespan upon HbA1c detection values in T2DM patients: modeling and internal-external verification.

To determine the effect of red blood cell (RBC) lifespan variability on glycosylated hemoglobin (HbA1c) measurements in type 2 diabetes mellitus (T2DM) individuals and develop a mathematical model for adjusting HbA1c values. We tracked glucose levels in 516 T2DM patients from Chu Hsien-I Memorial Hospital, categorized into Construction (n = 416) and Internal (n = 100) cohorts. Additionally, 165 participants from Tianjin diabetic retinopathy screening cohort, serving as the Independent cohort. RBC lifespan was determined using the CO breath test, and Hemoglobin glycation variation index (HGI) was calculated from the difference between measured and estimated HbA1c (eHbA1c). Model efficacy was evaluated using AUC, accuracy, sensitivity, and specificity. An inflection in the HGI-RBC lifespan model occurred at 66 days, with HbA1c underestimation when RBC lifespan was below 90 days, notably in the ≤ 66 days group. This underestimation increased the risk of cardiovascular and peripheral neuropathy complications. To rectify the impact of the shorter RBC lifespan in T2DM patients, the correction formula was established as HbA1c(c) = -0.05629×RBC lifespan + 1.127×HbA1c + 3.178 (R = 0.7360) in the ≤ 66 day lifespan group and HbA1c(c) = -0.004772 × RBC lifespan + 0.7569 × HbA1c + 2.394 (R = 0.7344) in the 67 to 89 day group. The corrected HbA1c models exhibited satisfactory predictive performance in all cohorts. Accurate adjustment for the effects of RBC lifespan on HbA1c values in T2DM patients is expected to enhance blood glucose management and the efficacious prevention and treatment of diabetes-associated complications. Chu Hsien-I Memorial Hospital of Tianjin Medical University, identifier ChiCTR2100046557.

Senescence and early-life performance as predictors of lifespan in a solitary bee

Performance tends to decline with age, including muscle function and stress tolerance. Yet, performance can vary widely among individuals within the same age group, showing that chronological age does not always represent biological age. To better understand ageing, we need to examine what drives some individuals to age faster than others. In order to achieve this, first we need to be able to predict whether an individual will have a long or short lifespan. In this study, we conducted a longitudinal study tracking individual-level locomotor activity, chill-coma recovery time, and metabolic rates, and assessed whether early-life performance is linked to lifespan using the solitary bee Megachile rotundata. We found that locomotor activity and chill-coma recovery times decline in old adults. However, resting metabolic rate did not change with age. We also found low cold tolerance and low mass at emergence in early-life are linked to shorter female lifespans, showing that early-life performance can explain some of the variation in lifespan in a population. Finally, these results also show that not all traits decline with age within the same species, and shed new light on sexual dimorphism in physiological traits and ageing.

Research on Lifespan Prediction Methods Using Ultrasonic Microimaging for Electronic Packaging

Addressing the issue of lifespan prediction for electronic packages under thermal loading, this paper proposes a method for predicting the lifespan of electronic packages based on ultrasonic microimaging. Firstly, experimental samples equipped with flip-chip packages were designed and fabricated and subjected to aging through thermal cycle acceleration tests. Ultrasonic microscopy was utilized to periodically acquire ultrasonic image data for monitoring solder joint degradation. Secondly, the internal ultrasonic wave propagation mechanism within electronic packages was investigated, establishing a qualitative relationship between the intensity in the central region of the solder joint’s ultrasonic image and internal defects within the joint. Image processing techniques were applied to enhance the quality of the solder joint images, and the mean intensity in the central region of the solder joint image was extracted as a failure feature. Finally, based on the extracted failure feature, a data-driven failure model for solder joints was developed, which predicts the lifespan of the solder joints based on cumulative failure probability. The research results indicate that the proposed model accurately describes the failure process of solder joints and effectively differentiates the lifespan variations among solder joints at different locations on the chip. This provides theoretical support for the reliability assessment of electronic package solder joints and holds practical value for enhancing the overall reliability of electronic packaging components.

Estimating power wheelchair electronics lifespan based on real-world data

Introduction Electronics are crucial to the operation and utility of power wheelchairs (PWCs). Existing research falls short in understanding electronics lifespan, which should inform proper maintenance and funding. Purpose This study investigates the lifespan of PWC electronics, aiming to estimate time until repair or replacement and identify contributing factors to variability in lifespan. Methods Retrospective data from 1268 group 2 PWCs, collected from the Wheelchair Repair Registry, were analysed using Kaplan–Meier’s survival analysis and Cox proportional hazards models. Results Results indicate that 29.2% of PWCs experienced electronics-related repairs, with a median survival of 32.2 months. Significant predictors of reduced electronics survival included device type (group 3 hazard ratio (HR), 1.58; p = .003), distribution year in 2017 (HR, 1.82; p < .001) and distribution year in 2018 (HR, 4.08; p < .001). Manufacturer D was a marginally significant factor in reduced survival (HR, 1.66, p = .070). Conclusion These findings underscore the importance of proper maintenance and design in enhancing PWC reliability and user quality of life. Future research should expand data inclusivity and consider broader implications for global PWC users.

Approach to the Patient: Diagnostic Challenges in the Workup for Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) affects 10% to 13% of women globally. It is a condition with metabolic, reproductive, and psychological features, with health impacts across the lifespan. The etiology of PCOS is complex, with an interplay of several factors, including genetic and epigenetic susceptibility, androgen exposure in early life and adiposity-related dysfunction leading to hypothalamic-ovarian disturbance. Diagnosis is recommended based on the International PCOS Guideline criteria, with diagnosis confirmed in adults when 2 of out the following 3 criteria are met: (i) hyperandrogenism (clinical or biochemical); (ii) irregular cycles; and (iii) polycystic ovary morphology or elevated anti-Müllerian hormone (AMH) levels. With its clinical heterogeneity, distinct phenotypes, variation across the lifespan and ethnic variation, PCOS diagnosis can present significant diagnostic challenges to clinicians.

How long Parasitidae (Acari: Parasitiformes: Mesostigmata) live?

Understanding the lifespan of organisms is fundamental to explaining their ecology, behaviour, and evolutionary dynamics. The present review provided a survey of the longevity and other life history data of the Parasitidae, a diverse family of mites known for their predatory and phoretic life strategies. This survey covered the influence of temperature and prey preferences as potential factors affecting lifespan variability within this taxonomic group. The findings reveal a wide longevity range, with developmental times ranging from 12 to over 60 days. Remarkably, the presence of phoretic deutonymphs complicates those estimations, with limited data on their maximal lifespan. Laboratory experiments suggest varied generation times, ranging from 8.5 to 10.2 days, yet often overlook the duration of deutonymph’s development and overwintering stage. This research contributes to a deeper understanding of the Parasitidae and underscores the importance of future studies on their life-history dynamics.

EVOLUTION OF LONGEVITY IN TETRAPODA: SAFETY IS MORE IMPORTANT THAN METABOLISM LEVEL

Various environmental morphological and behavioral factors may be decisive in the longevity of representatives of various taxa. Long-lived species develop systems aimed at increasing the body’s stability and defense, and ultimately increasing life expectancy. In addition, long-living species are characterized by different levels of manifestation of factors favorable to longevity (gerontological success): body size, slow metabolism, level of activity of the body’s repair systems and antioxidant defense systems, resistance to toxic substances and tumor formation, and the presence of neotenic characteristics. Continuing the work on mammals, in this work we studied the characteristics that distinguish long-lived ectotherms (crocodiles and turtles) and compared them with those of other representatives of ectotherms (squamates and amphibians) and endotherms (birds and mammals). The article also discusses mathematical indicators used to assess the predisposition to longevity in different species. These indicators include both standard ones (mortality rate, maximum lifespan, coefficient of variation of lifespan) and derivatives from them. evolutionary patterns of aging are further explained by protective phenotypes and life history strategies. The work assessed the relationship between lifespan and various studied factors, including body size and temperature, encephalization, protection of occupied econiches, the presence of protective structures (for example, shell and osteoderms), environmental temperature, etc.), and their influence on the distribution of lifespan as a statistical quantities. The hypothesis about the level of metabolism and temperature as the most determining factors of longevity was not confirmed. It turned out that animals protected by shells (turtles with their exceptional longevity) live longer than species that have poison or lack protective devices. The improvement of methods of defense against external threats in long-lived ectotherms is consistent with the characteristics of long-lived endotherms (for example, naked mole rats that live in tunnels underground, or bats and birds, whose ability to fly is also one of the best methods of defense).

CALCULATION OF AGING: ANALYSIS OF SURVIVAL CURVES IN NORMAL AND IN PATHOLOGY, FLUCTUATIONS IN MORTALITY DYNAMICS, CHARACTERISTICS OF LIFE SPAN DISTRIBUTION AND INDICATORS OF ITS VARIATION

The article describes the history of studies of survival data carried out at the Research Institute of Physico-Chemical Biology under the leadership of Academician V. P. Skulachev from 1970s until present, with special emphasis on the last decade. The use of accelerated failure time (AFT) model and analysis of coefficient of variation of lifespan (CVLS) in addition to the Gompertz methods of analysis, allows to assess survival curves for the presence of temporal scaling (i.e., manifestation of accelerated aging), without changing the shape of survival curve with the same coefficient of variation. A modification of the AFT model that uses temporal scaling as the null hypothesis made it possible to distinguish between the quantitative and qualitative differences in the dynamics of aging. It was also shown that it is possible to compare the data on the survival of species characterized by the survival curves of the original shape (i.e., “flat” curves without a pronounced increase in the probability of death with age typical of slowly aging species), when considering the distribution of lifespan as a statistical random variable and comparing parameters of such distribution. Thus, it was demonstrated that the higher impact of mortality caused by external factors (background mortality) in addition to the age-dependent mortality, the higher the disorder of mortality values and the greater its difference from the calculated value characteristic of developed countries (15-20%). For comparison, CVLS for the Paraguayan Ache Indians is 100% (57% if we exclude prepuberty individuals as suggested by Jones et al.). According to Skulachev, the next step is considering mortality fluctuations as a measure for the disorder of survival data. Visual evaluation of survival curves can already provide important data for subsequent analysis. Thus, Sokolov and Severin [1] found that mutations have different effects on the shape of survival curves. Type I survival curves generally retains their standard convex rectangular shape, while type II curves demonstrate a sharp increase in the mortality which makes them similar to a concave exponential curve with a stably high mortality rate. It is noteworthy that despite these differences, mutations in groups I and II are of a similar nature. They are associated (i) with “DNA metabolism” (DNA repair, transcription, and replication); (ii) protection against oxidative stress, associated with the activity of the transcription factor Nrf2, and (iii) regulation of proliferation, and (or these categories may overlap). However, these different mutations appear to produce the same result at the organismal level, namely, accelerated aging according to the Gompertz’s law. This might be explained by the fact that all these mutations, each in its own unique way, either reduce the lifespan of cells or accelerate their transition to the senescent state, which supports the concept of Skulachev on the existence of multiple pathways of aging (chronic phenoptosis).

Similarities and differences in the gene expression signatures of physiological age versus future lifespan.

Across all taxa of life, individuals within a species exhibit variable lifespans. Differences in genotype or environment are not sufficient to explain this variance, as even isogenic Caenorhabditis elegans nematodes reared under uniform conditions show significant variability in lifespan. To investigate this phenomenon, we used lifespan-predictive biomarkers to isolate, at mid-adulthood, prospectively long- and short-lived individuals from an otherwise identical population. We selected two biomarkers which correlated positively with lifespan, lin-4p::GFP and mir-243p::GFP, and two which correlated negatively, mir-240/786p::GFP and autofluorescence. The gene-expression signature of long versus short future lifespan was strikingly similar across all four biomarkers tested. Since these biomarkers are expressed in different tissues, these results suggest a shared connection to a global health state correlated with future lifespan. To further investigate this underlying state, we compared the transcriptional signature of long versus short future lifespan to that of chronologically young versus old individuals. By comparison to a high-resolution time series of the average aging transcriptome, we determined that subpopulations predicted to be long- or short-lived by biomarker expression had significantly different transcriptional ages despite their shared chronological age. We found that this difference in apparent transcriptional age accounted for the majority of differentially expressed genes associated with future lifespan. Interestingly, we also identified several genes whose expression consistently separated samples by biomarker expression independent of apparent transcriptional age. These results suggest that the commonalities in the long-lived versus short-lived state reported across different biomarkers of aging extends beyond simply transcriptionally young versus transcriptionally old.

Analysis of lifespan across Diversity Outbred mouse studies identifies multiple longevity-associated loci.

Lifespan is an integrative phenotype whose genetic architecture is likely to highlight multiple processes with high impact on health and aging. Here, we conduct a genetic meta-analysis of longevity in Diversity Outbred (DO) mice that includes 2,444 animals from three independently conducted lifespan studies. We identify six loci that contribute significantly to lifespan independently of diet and drug treatment, one of which also influences lifespan in a sex-dependent manner, as well as an additional locus with a diet-specific effect on lifespan. Collectively, these loci explain over half of the estimated heritable variation in lifespan across these studies and provide insight into the genetic architecture of lifespan in DO mice.

Aging at scale: Younger dogs and larger breeds from the Dog Aging Project show accelerated epigenetic aging.

Dogs exhibit striking within-species variability in lifespan, with smaller breeds often living more than twice as long as larger breeds. This longevity discrepancy also extends to health and aging-larger dogs show higher rates of age-related diseases. Despite this well-established phenomenon, we still know little about the biomarkers and molecular mechanisms that might underlie breed differences in aging and survival. To address this gap, we generated an epigenetic clock using DNA methylation from over 3 million CpG sites in a deeply phenotyped cohort of 864 companion dogs from the Dog Aging Project, including some dogs sampled annually for 2-3 years. We found that the largest breed size tends to have epigenomes that are, on average, 0.37 years older per chronological year compared to the smallest breed size. We also found that higher residual epigenetic age was significantly associated with increased mortality risk, with dogs experiencing a 34% higher risk of death for each year increase in residual epigenetic age. These findings not only broaden our understanding of how aging manifests within a diverse species but also highlight the significant role that demographic factors play in modulating the biological mechanisms underlying aging. Additionally, they highlight the utility of DNA methylation as both a biomarker for healthspan-extending interventions, a mortality predictor, and a mechanism for understanding inter-individual variation in aging in dogs.

Sex differences in clinically diagnosed psychiatric disorders over the lifespan: a nationwide register-based study in Sweden

Sex differences in clinically diagnosed psychiatric disorders over the lifespan: a nationwide register-based study in Sweden

The evolution of gestation length in eutherian mammals.

Eutherian mammals exhibit considerable variation in their gestation lengths, which has traditionally been linked to variation in other traits, including body mass and lifespan. To understand how gestation length variation, including its association with body mass and lifespan variation, changed over mammalian evolution, we conducted phylogeny-informed analyses of 845 representative extant species. We found that gestation length substantially differed in both whether and how strongly it was associated with body mass and lifespan across mammals. For example, gestation length was not associated with lifespan or body mass in Chiroptera and Cetacea but was strongly associated only with body mass in Carnivora. We also identified 52 evolutionary shifts in gestation length variation across the mammal phylogeny and 14 shifts when we jointly considered variation of all three traits; six shifts were shared. Notably, two of these shifts, both positive, occurred at the roots of Cetacea and Pinnipedia, respectively, coinciding with the transition of these clades to the marine environment, whereas a negative shift occurred at the root of Chiroptera, coinciding with the evolution of flight in this clade. These results suggest that the relationship between gestation length and the two other traits has varied substantially across mammalian phylogeny.

Breaking boundaries: A new era in glycemic assessment for type 2 diabetes patients

BACKGROUND: Glycemic control is essential in managing type 2 diabetes mellitus (T2DM) to reduce the risk of complications, including diabetic nephropathy. Traditionally, glycated hemoglobin (HbA1c) has been the gold standard for assessing long-term glycemic control. However, glycated albumin (GA) has emerged as a potential alternative due to its shorter lifespan and reduced sensitivity to erythrocyte lifespan changes. AIMS AND OBJECTIVES: This study aimed to compare the efficacy of GA and HbA1c in evaluating glycemic control in stable T2DM patients, particularly regarding its implications for diabetic nephropathy and associated complications. METHODOLOGY: A comparative analysis was conducted between GA and HbA1c levels in a cohort of stable T2DM patients. The primary focus was on assessing the reliability and clinical applicability of GA as a marker for glycemic control, especially in cases where HbA1c might provide misleading results. RESULTS: The study findings indicated that GA could offer a valuable alternative for glycemic monitoring, especially in clinical scenarios where HbA1c might not accurately reflect glycemic status due to erythrocyte lifespan variations. The use of GA could enhance the precision of glycemic control assessment, thus potentially improving patient care. CONCLUSION: The results underscore the importance of incorporating GA in clinical practice as an adjunct to HbA1c, particularly in situations where HbA1c may be unreliable. GA provides a promising alternative for better management of glycemic control in T2DM patients, potentially impacting the management and progression of diabetic nephropathy.

Polygenic prediction of human longevity on the supposition of pervasive pleiotropy

The highly polygenic nature of human longevity renders pleiotropy an indispensable feature of its genetic architecture. Leveraging the genetic correlation between aging-related traits (ARTs), we aimed to model the additive variance in lifespan as a function of the cumulative liability from pleiotropic segregating variants. We tracked allele frequency changes as a function of viability across different age bins and prioritized 34 variants with an immediate implication on lipid metabolism, body mass index (BMI), and cognitive performance, among other traits, revealed by PheWAS analysis in the UK Biobank. Given the highly complex and non-linear interactions between the genetic determinants of longevity, we reasoned that a composite polygenic score would approximate a substantial portion of the variance in lifespan and developed the integrated longevity genetic scores (iLGSs) for distinguishing exceptional survival. We showed that coefficients derived from our ensemble model could potentially reveal an interesting pattern of genomic pleiotropy specific to lifespan. We assessed the predictive performance of our model for distinguishing the enrichment of exceptional longevity among long-lived individuals in two replication cohorts (the Scripps Wellderly cohort and the Medical Genome Reference Bank (MRGB)) and showed that the median lifespan in the highest decile of our composite prognostic index is up to 4.8 years longer. Finally, using the proteomic correlates of iLGS, we identified protein markers associated with exceptional longevity irrespective of chronological age and prioritized drugs with repurposing potentials for gerotherapeutics. Together, our approach demonstrates a promising framework for polygenic modeling of additive liability conferred by ARTs in defining exceptional longevity and assisting the identification of individuals at a higher risk of mortality for targeted lifestyle modifications earlier in life. Furthermore, the proteomic signature associated with iLGS highlights the functional pathway upstream of the PI3K-Akt that can be effectively targeted to slow down aging and extend lifespan.

Facile preparation of MnO/Mn3O4 anode from commercial manganese(II) oxalate dihydrate and its advanced lithium storage performance

Facile preparation of MnO/Mn3O4 anode from commercial manganese(II) oxalate dihydrate and its advanced lithium storage performance