Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
147
datasets available to search
ShareScore release 0.9.0
Dataset results
147 results for “telomere length”
Supplementary data for "Effect of Human Disturbance on Bird Telomere Length: An Experimental Approach"
<p><strong>Abstract</strong></p> <p>Human recreational activities increase worldwide in space and frequency leading to higher rates of encounter between humans and wild animals. Because wildlife often perceive humans as predators, this increase in human disturbance may have negative consequences for the individuals and also for the viability of populations. Up to now, experiments on the effects of human disturbance on wildlife have mainly focused on individual behavioral and stress-physiological reactions, on breeding success, and on survival. However, the effects on other physiological parameters and trans-generational effects remain poorly understood. We used a low-intensity experimental disturbance in the field to explore the impacts of human disturbance on telomere length in great tit (<em>Parus major</em>) populations and found a clear effect of disturbance on telomere length. Adult males, but not females, in disturbed plots showed shorter telomere lengths when compared to control plot. Moreover, variation in telomere length of adult great tits was reflected in the next generation, as we found a positive correlation between telomere length of the chicks and of their fathers. Given that telomere length has been linked to animal lifespan, our study highlights that activities considered to be of little concern (i.e., low levels of disturbance) can have a long-lasting impact on the physiology and survival of wild animals and their next generation.</p>
TARA-PACIFIC_telomere-length
<p>Samples : High molecular weigth DNA was extracted from an apex of coral nubbins from the TARA-Pacific CS40 sampling. Telomere length was measured using Telomere Restriction Fragment assay using radioactive probes to measure the host telomere length sequence (TTAGGG)<sub>n</sub>, also referred as T2, or the symbionts telomere length sequence (TTTAGGG)<sub>n</sub>, also referred as T3.</p> <p>Measurements was successfully performed for the host telomere repeat sequence on 1098 samples, for the symbiont repeat sequence on 882 samples, measurements were successfully performed several times with the host telomere probe for 248 samples and with the symbiont telomere probe for 115 samples.</p> <p> </p> <p> </p> <p><strong>File structure</strong></p> <p>Variables :</p> <p><strong>1-sampleID</strong>: TARA PACIFIC Colony ID barcod</p> <p><strong>2- sampling-design:</strong> TARA PACIFIC Colony ID encoding for sampling, the island, site and colony (ex: OA000-I01S01C001 stands for Island 1, site 1 and coral colony 1)</p> <p><strong>3-n: </strong>Number of measurements done with the host telomere probe (TTAGGG)<sup>*</sup>.</p> <p><strong>4- Mean:</strong> Host mean telomere length measured in kilobases.<sup>*</sup></p> <p><strong>5- standard-deviation: </strong>Standard deviation of the mean measured between the number of measurements done with the host telomere probe (TTAGGG)<sup>*</sup>.</p> <p><strong>6-percentile-50:</strong> Host median telomere length measured in kilobases.<sup>*</sup></p> <p><strong>7-percentile-75:</strong> Host 3<sup>rd</sup> quartile telomere length limit below which lies 75% of the signal, measured in kilobases.<sup>*</sup></p> <p><strong>8-percentile-25:</strong> Host 1<sup>st</sup> quartile telomere length limit below which lies 25% of the signal, measured in kilobases.<sup>*</sup></p> <p><strong>9-interpercentile-p75-p25-distance:</strong> Distance between host_percentile-25 and host_percentile-75 telomere length, measured in kilobases.<sup>*</sup></p> <p><strong>10-n: </strong>Number of measurements done with the symbiont telomere probe (TTTAGGG)<sup>*</sup>.</p> <p><strong>4- Mean:</strong> Symbiont mean telomere length measured in kilobases.<sup>*</sup></p> <p><strong>5- standard-deviation: </strong>Standard deviation of the mean measured between the number of measurements done with the symbiont telomere probe (TTAGGG)<sup>*</sup>.</p> <p><strong>6-percentile-50:</strong> Symbiont median telomere length measured in kilobases.<sup>*</sup></p> <p><strong>7-percentile-75:</strong> Symbiont 3<sup>rd</sup> quartile telomere length limit below which lies 75% of the signal, measured in kilobases.<sup>*</sup></p> <p><strong>8-percentile-25:</strong> Symbiont 1<sup>st</sup> quartile telomere length limit below which lies 25% of the signal, measured in kilobases.<sup>*</sup></p> <p><strong>9-interpercentile-p75-p25-distance:</strong> Distance between symbiont_percentile-25 and symbiont_percentile-75 telomere length, measured in kilobases.<sup>*</sup></p> <p><strong><em><sup>*</sup></em></strong><em> When signal was undetected measurements is encoded by “not available”.</em></p>
Data from: Telomere length declines with age, but relates to immune function independent of age in a wild passerine
<p><span>Telomere length (TL) shortens with age but telomere dynamics can relate to fitness components independent of age. Immune function often relates to such fitness components and can also interact with telomeres. Studying the link between TL and immune function may therefore help us understand telomere-fitness associations. We assessed the relationships between erythrocyte TL and four immune indices (haptoglobin, natural antibodies, complement activity, heterophil-lymphocyte ratio; n=477-589), from known-aged individuals of a wild passerine (<em>Malurus coronatus</em>). As expected, we find that TL significantly declined with age. To verify whether associations between TL and immune function were independent of parallel age-related changes (e.g. immunosenescence), we statistically controlled for sampling age, and used within-subject centring of TL to separate relationships within or between individuals. We found that TL positively predicted complement activity at the between-individual level (individuals with longer average TL had higher complement activity), but no other immune indices. In contrast, age predicted levels of natural antibodies and heterophil-lymphocyte ratio, allowing inference that respective associations between TL and age with immune indices are independent. Any links existing between TL and fitness are therefore unlikely to be strongly mediated by innate immune function, while TL and immune indices appear independent expressions of individual heterogeneity.</span></p>
Are urbanization and brood parasitism associated with differences in telomere lengths in song sparrows?
<p>Urbanization reflects a major form of environmental change impacting wild birds globally. Whereas urban habitats may provide increased availability of water, some food items, and reduced predation levels compared to rural, they can also present novel stressors including increased light at night, ambient noise, and reduced nutrient availability. Urbanization can also alter levels of brood parasitism, with some host species experiencing elevated levels of brood parasitism in urban areas compared to rural areas. Though the demographic and behavioral consequences of urbanization and brood parasitism have received considerable attention, their consequences for cellular-level processes are less understood. Telomeres provide an opportunity to understand the cellular consequences of different environments as they are a well-established metric of biological state that can be associated with residual lifespan, disease risk, and behaviour, and are known to be sensitive to environmental conditions. Here we examine the relationships between urbanization, brood parasitism, and blood telomere lengths in adult and nestling song sparrows (Melospiza melodia). Song sparrows are a North American songbird found in both urban and rural habitats that experience high rates of brood parasitism by brown-headed cowbirds (Molothrus ater) in the urban, but not the rural, sites in our study system. Among adults and nestlings from non-parasitized nests, we found no differences in relative telomere lengths between urban and rural habitats. However, among urban nestlings, the presence of a brood parasite in the nest was associated with significantly shorter relative telomere lengths compared to when a brood parasite was absent. Our results suggest a novel, indirect, impact of urbanization on nestling songbirds through the physiological impacts of brood parasitism.</p>
Data for: Effects of long-term ethanol storage of blood samples on the estimation of telomere length
<p>Telomeres, DNA structures located at the end of eukaryotic chromosomes, shorten with each cellular cycle. The shortening rate is affected by factors associated with stress, and, thus telomere length has been used as a biomarker of ageing, disease, and different life history trade-offs. Telomere research has received much attention in the last decades; however, there is still a wide variety of factors that may affect telomere measurements and to date no study has thoroughly evaluated the possible long-term effect of a storage medium on telomere measurements. In this study we evaluated the long-term effects of ethanol on relative telomere length (RTL) measured by qPCR, using blood samples of magpies collected over twelve years and stored in absolute ethanol at room temperature. We firstly tested whether storage time had an effect on RTL and secondly we modelled the effect of time of storage (from 1 to 12 years) in differences in RTL from DNA extracted twice in consecutive years from the same blood sample. We also tested whether individual amplification efficiencies were influenced by storage time, and whether this could affect our results. Our study provides evidence of an effect of storage time on telomere length measurements. Importantly, this effect shows a pattern of decreasing loss of telomere sequence with storage time that stops after approximate 4 years of storage, which suggests that telomeres may degrade in blood samples stored in ethanol. Our method to quantify the effect of storage time could be used to evaluate other storage buffers and methods. Our results highlight the need to evaluate the long-term effects of storage on telomere measurements, particularly in long-term studies.</p>
Data from: Sex-specific variation in foraging behavior is related to telomere length in a long-lived seabird
Open the record for dataset details and reuse information.
Hidden causes of variation in offspring reproductive value: negative effects of maternal breeding age on offspring telomere length persist undiminished across multiple generations
Open the record for dataset details and reuse information.
Are urbanization and brood parasitism associated with differences in telomere lengths in song sparrows?
Open the record for dataset details and reuse information.
Data for: Effects of long-term ethanol storage of blood samples on the estimation of telomere length
Open the record for dataset details and reuse information.
Data from: Telomere length declines with age, but relates to immune function independent of age in a wild passerine
Open the record for dataset details and reuse information.
Scatter plot diagram to demonstrate correlation between relative telomere length (RTL) and age.
<p><strong>Figure S1. </strong>Scatter plot diagram to demonstrate correlation between relative telomere length (RTL) and age.</p>
Scatter plot diagram to demonstrate correlation between relative telomere length (RTL) and age.
<p><strong>Figure S1. </strong>Scatter plot diagram to demonstrate correlation between relative telomere length (RTL) and age.</p>
Data from: Sex-specific effects of experimental ectoparasite infestation on telomere length in great tit nestlings
<p>Telomere length is a biomarker of biological ageing and lifespan in various vertebrate taxa. Evidence is accumulating that telomeres shorten more rapidly when an individual is exposed to environmental stressors. Parasites are potent selective agents that can cause physiological stress directly or indirectly through the activation of the host's immune system. Yet to date, empirical evidence for a role of parasites in telomere dynamics in natural populations is limited.</p> <p>Here we show experimentally that exposure to ectoparasitic hen fleas (<i>Ceratophyllus gallinae</i>) during growth results in shorter telomeres in female, but not male, great tit (<i>Parus major</i>) nestlings. Females had significantly longer telomeres than males when growing up in experimentally deparasitized nests but because of the sex-specific effects of parasitism on telomere length, this sexual dimorphism was absent in birds growing up in experimentally infested nests. Our results provide the first experimental evidence for a role of ectoparasitism in telomere dynamics in a natural vertebrate population, and suggest that the costs of infection manifest in sex-specific ways.</p>
A putative telomerase activator has tissue-specific effects on telomere length in a developing songbird
<p>There is good evidence that telomeres predict variation in health and longevity, yet it is unclear whether these patterns are causally derived from telomeres <i>per se</i>, in part because relatively little research directly manipulates telomere length during early life, when telomere shortening is most dynamic. Here, we test how the telomerase activator TA-65 (i.e., cycloastrogenol) affects telomere length in five tissues during the peak of growth in the wild tree swallow (<i>Tachycineta bicolor</i>). Following 8 days of oral TA-65 administration, chicks experienced telomere lengthening in the blood and accelerated feather growth, but no changes to mass over time. TA-65 did not affect telomere length in the brain or spleen and led to shorter telomeres in the liver and adrenals. This whole-organism experimental manipulation of telomere dynamics therefore reveals limitations to telomere protection and biological senescence. In doing so, this work advances our understanding of early-life telomere dynamics and their potential role in generating future variation in health and lifespan.</p>
Data from: Offspring telomere length in the long lived Alpine swift is negatively related to the age of their biological father and foster mother
A growing body of studies is showing that offspring telomere length (TL) can be influenced by the age of their parents. Such a relationship might be explained by variation in TL at conception (gamete effect) and/or by alteration of early growth conditions in species providing parental care. In a long-lived bird with bi-parental care, the Alpine swift (Apus melba), we exchanged an uneven number of 2 to 4-day-old nestlings between pairs as part of a brood size manipulation. Nestling TL was measured at 50 days after hatching, which allowed investigation of the influence of the age of both their biological and foster parents on offspring TL, after controlling for the manipulation. Nestling TL was negatively related to the age of their biological father and foster mother. Nestling TL did not differ between enlarged and reduced broods. These findings suggest that offspring from older males were fertilized by gametes with shorter telomeres, presumably due to a greater cell division history or a longer accumulation of damage, and that older females may have provided poorer parental care to their offspring.
Anthropogenic noise is associated with telomere length and carotenoid-based coloration in free-living nestling songbirds
<p>Growing evidence suggests that anthropogenic noise has deleterious effects on the behavior and physiology of free-living animals. These effects may be particularly pronounced early in life, when developmental trajectories are sensitive to stressors, yet studies investigating developmental effects of noise exposure in free-living populations remain scarce. To elucidate the effects of noise exposure during development, we examined whether noise exposure is associated with shorter telomeres, duller carotenoid-based coloration and reduced body mass in nestlings of a common urban bird, the great tit (Parus major). We also assessed how the noise environment is related to reproductive success. We obtained long-term measurements of the noise environment, over a ~24-h period, and characterized both the amplitude (measured by LAeq, LA90, LA10, LAmax) and variance in noise levels, since more stochastic, as well as louder, noise regimes might be more likely to induce stress. In our urban population, noise levels varied substantially, with louder, but less variable, noise characteristic of areas adjacent to a highway. Noise levels were also highly repeatable, suggesting that individuals experience consistent differences in noise exposure. The amplitude of noise near nest boxes was associated with shorter telomeres among smaller, but not larger, brood members. In addition, carotenoid chroma and hue were positively associated with variance in average and maximum noise levels, and average reflectance was negatively associated with variance in background noise. Independent of noise, hue was positively related to telomere length. Nestling mass and reproductive success were unaffected by noise exposure. Results indicate that multiple dimensions of the noise environment, or factors associated with the noise environment, could affect the phenotype of developing organisms, that noise exposure, or correlated variables, might have the strongest effects on sensitive groups of individuals, and that carotenoid hue could serve as a signal of early-life telomere length.</p>
Data from: Sex- and tissue-specific differences in telomere length in a reptile
The usage of telomere length (TL) in blood as a proxy for the TL of other tissues relies on the assumption that telomere dynamics across all tissues are similar. However, telomere attrition can be caused by reactive oxygen species (ROS) which may vary with metabolic rate, which itself varies across organs depending upon the life history strategy of an organism. Thus we chose to measure the telomeres of various cell types in juvenile painted dragon lizards, Ctenophorus pictus, given their unusual life history strategy. Individuals typically only experience a single mating season. We measured the TL of male and female dragons using qPCR and observed that TL varied with tissue type and sex. Telomeres of blood cells were longer than those of liver, heart, brain, and spleen, and females had longer telomeres than males. Brain telomeres in males were approximately half the length of those in females. Telomeric attrition in the male brain may be due to the need for rapid learning of reproductive tactics (territory patrol and defence, mate-finding). Significant correlations between the TL of tissue types suggest that blood TL may be a useful proxy for the TL of other tissues. Our comparison of organ-specific telomere dynamics, the first in a reptile, suggests that the usage of blood TL as a proxy requires careful consideration of the life history strategy of the organism.
Artificial size selection experiment reveals telomere length dynamics and fitness consequences in a wild passerine
<p>Telomere dynamics could underlie life-history trade-offs among growth, size, and longevity, but our ability to quantify such processes in natural, unmanipulated populations is limited. We investigated how 4 years of artificial selection for either larger or smaller tarsus length, a proxy for body size, affected early-life telomere length (TL) and several components of fitness in two insular populations of wild house sparrows over a study period of 11 years. The artificial selection was expected to shift the populations away from their optimal body size and increase the phenotypic variance in body size. Artificial selection for larger individuals caused TL to decrease, but there was little evidence that TL increased when selecting for smaller individuals. There was a negative correlation between nestling TL and tarsus length under both selection regimes. Males had longer telomeres than females and there was a negative effect of harsh weather on TL. We then investigated whether changes in TL might underpin fitness effects due to the deviation from the optimal body size. Mortality analyses indicated disruptive selection on TL because both short and long early-life telomeres tended to be associated with the lowest mortality rates. In addition, there was a tendency for a negative association between TL and annual reproductive success, but only in the population where body size was increased experimentally. Our results suggest that natural selection for optimal body size in the wild may be associated with changes in TL during growth, which is known to be linked to longevity in some bird species.</p>
Causes and consequences of variation in early‐life telomere length in a bird metapopulation
<p><span>Environmental conditions during early-life development can have lasting effects shaping individual heterogeneity in fitness and fitness-related traits. The length of telomeres, the DNA sequences protecting chromosome ends, may be affected by early-life conditions, and telomere length (TL) has been associated with individual performance within some wild animal populations. Thus, knowledge of the mechanisms that generate variation in TL, and the relationship between TL and fitness, is important in understanding the role of telomeres in ecology and life-history evolution. Here, we investigate how environmental conditions and morphological traits are associated with early-life blood TL and if TL predicts natal dispersal probability or components of fitness in 2746 wild house sparrow (<em>Passer domesticus</em>) nestlings from two populations sampled across 20 years (1994-2013). We retrieved weather data and we monitored population fluctuations, individual survival, and reproductive output using field observations and genetic pedigrees. We found a negative effect of population density on TL, but only in one of the populations. There was a curvilinear association between TL and the maximum daily North Atlantic Oscillation index during incubation, suggesting that there are optimal weather conditions that result in the longest TL. Dispersers tended to have shorter telomeres than non-dispersers. TL did not predict survival, but we found a tendency for individuals with short telomeres to have higher annual reproductive success. Our study showed how early-life TL is shaped by effects of growth, weather conditions, and population density, supporting that environmental stressors negatively affect TL in wild populations. In addition, shorter telomeres may be associated with a faster pace-of-life, as individuals with higher dispersal rates and annual reproduction tended to have shorter early-life TL.</span></p>
Data for: Telomere length predicts timing and intensity of migratory behavior in a nomadic songbird
<p>Our understanding of state-dependent behavior is reliant on identifying physiological indicators of condition. Telomeres are of growing interest for understanding behavior as they capture differences in biological state and residual lifespan. To understand the significance of variable telomere lengths for behavior and test two hypotheses describing the relationship between telomeres and behavior (i.e., the causation and the selective adoption hypotheses), we assessed if telomere lengths are longitudinally repeatable traits related to spring migratory behavior in captive pine siskins (<em>Spinus pinus</em>). Pine siskins are nomadic songbirds that exhibit highly flexible, facultative migrations, including a period of spring nomadism. Captive individuals exhibit extensive variation in spring migratory restlessness and are an excellent system for mechanistic studies of migratory behavior. Telomere lengths were found to be significantly repeatable (R = 0.51) over 4 months, and shorter pre-migratory telomeres were associated with earlier and more intense expression of spring nocturnal migratory restlessness. Telomere dynamics did not vary with migratory behavior. Our results describe the relationship between telomere length and migratory behavior and provide support for the selective adoption hypothesis. More broadly, we provide a novel perspective on the significance of variable telomere lengths for animal behavior and the timing of annual cycle events.</p>
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.