scholarly journals Nestling telomere length does not predict longevity, but covaries with adult body size in wild barn swallows

2013 ◽  
Vol 9 (5) ◽  
pp. 20130340 ◽  
Author(s):  
Manuela Caprioli ◽  
Maria Romano ◽  
Andrea Romano ◽  
Diego Rubolini ◽  
Rosita Motta ◽  
...  
Keyword(s):  
Body Size ◽  
Telomere Length ◽  
Large Body ◽  
Telomere Shortening ◽  
Rearing Conditions ◽  
Age Dependent ◽  
In The Wild ◽  
Barn Swallows ◽  
The Cost

Telomere length and dynamics are increasingly scrutinized as ultimate determinants of performance, including age-dependent mortality and fecundity. Few studies have investigated longevity in relation to telomere length (TL) in the wild and none has analysed longevity in relation to TL soon after hatching, despite the fact that telomere shortening may mostly occur early in life. We show that TL in nestling barn swallows ( Hirundo rustica ) in the wild does not predict longevity. However, TL positively covaries with body size, suggesting that individuals with large TL can afford to grow larger without paying the cost of reduced TL, and/or that benign rearing conditions ensure both large body size and low rates of telomere shortening. Overall, our study hints at a role of TL in developmental processes, but also indicates a need for further analyses to assess the expectation that TL in young individuals predicts longevity in the wild.

scholarly journals Cope's Rule and Romer's theory: patterns of diversity and gigantism in eurypterids and Palaeozoic vertebrates

2009 ◽  
Vol 6 (2) ◽  
pp. 265-269 ◽  
Author(s):  
James C. Lamsdell ◽  
Simon J. Braddy
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Feeding Strategy ◽  
Large Body ◽  
Large Body Size ◽  
Causal Mechanisms ◽  
Family Level ◽  
Cope’S Rule ◽  
Abiotic Environmental Factors

Gigantism is widespread among Palaeozoic arthropods, yet causal mechanisms, particularly the role of (abiotic) environmental factors versus (biotic) competition, remain unknown. The eurypterids (Arthropoda: Chelicerata) include the largest arthropods; gigantic predatory pterygotids (Eurypterina) during the Siluro-Devonian and bizarre sweep-feeding hibbertopterids (Stylonurina) from the Carboniferous to end-Permian. Analysis of family-level originations and extinctions among eurypterids and Palaeozoic vertebrates show that the diversity of Eurypterina waned during the Devonian, while the Placodermi radiated, yet Stylonurina remained relatively unaffected; adopting a sweep-feeding strategy they maintained their large body size by avoiding competition, and persisted throughout the Late Palaeozoic while the predatory nektonic Eurypterina (including the giant pterygotids) declined during the Devonian, possibly out-competed by other predators including jawed vertebrates.

Telomere Length Among the Elderly and Oldest-Old

2005 ◽  
Vol 8 (5) ◽  
pp. 425-432 ◽  
Author(s):  
Claus Bischoff ◽  
Jesper Graakjaer ◽  
Hans Christian Petersen ◽  
Bernard Jeune ◽  
Vilhelm A. Bohr ◽  
...  
Keyword(s):  
Telomere Length ◽  
Oldest Old ◽  
The Elderly ◽  
Specific Difference ◽  
Cross Sectional ◽  
Telomere Shortening ◽  
Telomere Sequence ◽  
Age Dependent ◽  
The Mean ◽  
Telomere Loss

AbstractHuman chromosomes terminate in a number of repeats of the sequence TTAGGG. At birth, each chromosome end is equipped with approximately 15 kb of telomere sequence, but this sequence is shortened during each cell division. In cell cultures telomere shortening is associated with senescence, a phenomenon that has also been observed in normal adult tissues, indicating that telomere loss is associated with organismal ageing. Previous work has established that the rate of telomere loss in humans is age dependent, and recent work shows a sex-specific difference in telomere length and shortening in individuals over the age span of 20 to 75 years. Here, terminal restriction fragment lengths on DNA purified from whole blood were measured to examine the mean telomere length in a cross-sectional cohort of 816 Danish individuals of age 73 to 101 years. In this age group, females show a linear correlation between telomere length and age, whereas the pattern tends to be nonlinear (quadratic in age) for males. This difference in telomere length dynamics between the 2 sexes may be caused by several different mechanisms, including differences in selection by mortality, differences in leukocyte population or different telomerase expression pattern.

scholarly journals Nijmegen Breakage Syndrome (NBS) is a Telomeropathy: Analysis of Telomere Length in NBS Homo- and Heterozygotes and Humanized Nbs Mice

2019 ◽  
Author(s):  
Raneem Habib ◽  
Ryong Kim ◽  
Heidemarie Neitzel ◽  
Ilja Demuth ◽  
Krystyna Chrzanowska ◽  
...  
Keyword(s):  
Telomere Length ◽  
Cancer Incidence ◽  
Genetic Instability ◽  
Nijmegen Breakage Syndrome ◽  
Survival Times ◽  
Telomere Shortening ◽  
Cancer Rate ◽  
Telomere Attrition ◽  
After Cancer

AbstractThe autosomal recessive genetic disorder Nijmegen breakage syndrome (NBS) is characterized by a defect in DNA double-strand break repair protein nibrin and chromosome instability associated with a high predisposition to cancer. Here we hypothesized that impaired nibrin/MRE11/RAD50 telomere maintenance complex may also affect telomere length and modulate the cancer phenotype.Telomere length was studied in blood from 38 homozygous and 27 heterozygous individuals, in one homozygous fetus, and in sex NBS lymphoblastoid cell lines (all with the founder mutation c.657_661del5), and in three humanized Nbs mice, using qPCR, TRF and Q-FISH.Telomere lengths were markedly but uniformly reduced to 20-40% of healthy controls. There was no correlation between telomere length and severity of clinical phenotype or age of death. By contrast, individual patients with very short telomeres displayed long survival times after cancer manifestation. Mildly accelerated telomere attrition was found in older NBS heterozygotes. In the NBS-fetus, the spinal cord, brain and heart had the longest telomeres, skin the shortest. Humanized Nbs mice (with much longer telo-meres than those in human beings) did not show accelerated telomere attrition.Our data clearly show that NBS is a secondary telomeropathy with unique features. Te- lomere attrition in NBS may cause genetic instability and contribute to the high cancer incidence in NBS. On the other hand, short telomeres may prevent an even worse pheno-type when a tumor has developed. These data may help to understand the high cancer rate in NBS and also the bifunctional role of telomere shortening in cancerogenesis.Author SummaryDNA damage is harmful because it leads to mutations in genes that initiate or accelerate cancerogenesis. The devastating consequences of DNA damage are manifested in diseases with non-functional repair pathways such as Nijmegen breakage syndrome (NBS). A common feature of these diseases is a high tumor incidence. However, cancer incidence varies and is not clear why it is highest for NBS. In a previous study, we have shown that the underlying nebrin mutation not only leads to defective DNA repair but also to higher degree of oxidative stress that generates further DNA lesions. Nibrin may play also an important role in protecting chromosome ends, the telomeres, from inap-propriate DNA repair. Therefore we examined the telomere length in NBS and show markedly reduced values in affected patients but not in NBC mice (with much milder phenotype and longer telomeres). Telomere attrition contributes to genetic instability and may thus contribute to the high cancer incidence in NBS. Individual patients with very short telomeres, however, displayed long survival times after cancer manifestation. Thus, short telomeres may also prevent an even worse phenotype when a tumor has developed. These data are fundamental to understanding the high cancer rate in NBS and also the bifunctional role of telomere shortening in cancer.

scholarly journals Evolution of body size and wing shape trade-offs in arsenurine silkmoths

2020 ◽  
Author(s):  
Chris A. Hamilton ◽  
Nathalie Winiger ◽  
Juliette J. Rubin ◽  
Jesse Breinholt ◽  
Rodolphe Rougerie ◽  
...  
Keyword(s):  
Body Size ◽  
Phylogenetic Signal ◽  
Large Body ◽  
Wing Shape ◽  
Phylogenetic Networks ◽  
Biological Research ◽  
Target Capture ◽  
Trade Offs ◽  
In The Wild ◽  
Shape Complexity

AbstractOne of the key objectives in biological research is understanding how evolutionary processes have produced Earth’s biodiversity. These processes have led to a vast diversity of wing shapes in insects; an unanswered question especially pronounced in moths. As one of the major predators of nocturnal moths, bats are thought to have been involved in a long evolutionary arms race with their prey. In response, moths are thought to have evolved many counter strategies, such as diverse wing shapes and large body sizes. However, the tradeoffs between body size and wing shape are not well understood. Here we examined the evolution of wing shape in the wild silkmoth subfamily Arsenurinae (Saturniidae). By using phylogenomics and geometric morphometrics, we established the framework to evaluate potential evolutionary relationships between body size and wing shape. The phylogeny was inferred based on 781 loci from target capture data of 42 arsenurine species representing all 10 recognized genera.We found there are evolutionary trade-offs between body size, wing shape, and the interaction of fore- and hindwing shape. Namely, body size decreases with increasing hindwing length, but increases as forewing shape becomes more complex. Additionally, hindwing shape has a significant effect on forewing shape complexity. The complex wing shapes that make Arsenurinae, and silkmoths as a whole, so charismatic are likely driven by the strong forces of natural selection and genomic constraints.One other important outcome was discovering within our data one of the most vexing problems in phylogenetic inference – a region of a tree that possesses short branches and no “support” for relationships (i.e., a polytomy). These parts of the Tree of Life are often some of the most interesting from an evolutionary standpoint. To investigate this problem, we used reciprocal illumination to determine the most probable generic relationships within the Arsenurinae by inspecting differing phylogenetic inferences, alternative support values, quartets, and phylogenetic networks to reveal hidden phylogenetic signal.

scholarly journals The role of past experience in development of feeding behavior in common vampire bats

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7448 ◽  
Author(s):  
Jineth Berrío-Martínez ◽  
Samuel Kaiser ◽  
Michelle Nowak ◽  
Rachel A. Page ◽  
Gerald G. Carter
Keyword(s):  
Life History Strategy ◽  
Past Experience ◽  
Short Term ◽  
Blood Temperature ◽  
Age Dependent ◽  
Vampire Bats ◽  
In The Wild ◽  
Foraging Skills

The life history strategy of common vampire bats (Desmodus rotundus) suggests that learning might play a role in development of their foraging skills. We took advantage of 12 captive births in a study colony of vampire bats to test the role of past experience in two aspects of feeding. First, we compared preferences for blood temperature in 32 wild-born vampire bats versus 11 captive-born vampire bats that had only previously fed on blood of ambient temperature or colder. We found no evidence for a preference in either group for blood presented at 4 °C versus 37 °C. Second, we tested whether captive-born vampire bats with no previous experience of feeding on live animals could successfully feed on a live chicken. Five of 12 naïve captive-born bats were able to bite the chicken and draw blood, but only one bat gained more than 5% of body mass. We were unable to reasonably compare their feeding performance with that of wild-born bats because only two of three wild-born, short-term captive bats fed on the chicken and none of the seven wild-born, long-term captive mothers attempted to feed. This unexpected lack of feeding might be due to a previously reported age-dependent neophobia. When six of the captive-born bats were released in the wild, they appeared to feed successfully because they survived for more than three consecutive nights. We suggest further tests that would better clarify the role of learning in the development of foraging in vampire bats.

Telomere dynamics in Fancg-deficient mouse and human cells

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 3927-3935 ◽  
Author(s):  
Sonia Franco ◽  
Henri J. van de Vrugt ◽  
Piedad Fernández ◽  
Miguel Aracil ◽  
Fre Arwert ◽  
...  
Keyword(s):  
Telomere Length ◽  
Bone Marrow Cells ◽  
Human Cells ◽  
Telomere Maintenance ◽  
Deficient Mouse ◽  
Early Passage ◽  
Telomere Shortening ◽  
Hematopoietic Stem ◽  
Telomere Dynamics

Abstract A number of DNA repair proteins also play roles in telomere metabolism. To investigate whether the accelerated telomere shortening reported in Fanconi anemia (FA) hematopoietic cells relates to a direct role of the FA pathway in telomere maintenance, we have analyzed telomere dynamics in Fancg-deficient mouse and human cells. We show here that both hematopoietic (stem and differentiated bone marrow cells, B and T lymphocytes) and nonhematopoietic (germ cells, mouse embryonic fibroblasts [MEFs]) Fancg-/- mouse cells display normal telomere length, normal telomerase activity, and normal chromosome end-capping, even in the presence of extensive clastogen-induced cytogenetic instability (mitomycin C [MMC], gamma-radiation). In addition, telomerase-deficient MEFs with humanlike telomere length and decreased Fancg expression (G5 Terc-/-/Fancg shRNA3 MEFs) display normal telomere maintenance. Finally, early-passage primary fibroblasts from patients with FA of complementation group G as well as primary human cells with reduced FANCG expression (FANCG shRNA IMR90 cells) show no signs of telomere dysfunction. Our observations indicate that accelerated telomere shortening in patients with FA is not due to a role of FANCG at telomeres but instead may be secondary to the disease. These findings suggest that telomerase-based therapies could be useful prophylactic agents in FA aplastic anemia by preserving their telomere reserve in the context of the disease. (Blood. 2004;104:3927-3935)

scholarly journals Chromosome specific telomere lengths and the minimal functional telomere revealed by nanopore sequencing

2021 ◽  
Author(s):  
Samantha L. Sholes ◽  
Kayarash Karimian ◽  
Ariel Gershman ◽  
Thomas J. Kelly ◽  
Winston Timp ◽  
...  
Keyword(s):  
Telomere Length ◽  
Clonal Variation ◽  
Nanopore Sequencing ◽  
Biological Mechanisms ◽  
Specific Chromosome ◽  
Telomere Shortening ◽  
Long Read ◽  
Length Regulation ◽  
Telomere Length Regulation

We developed a method to tag telomeres and measure telomere length by nanopore sequencing in the yeast S. cerevisiae. Nanopore allows long read sequencing through the telomere, subtelomere and into unique chromosomal sequence, enabling assignment of telomere length to a specific chromosome end. We observed chromosome end specific telomere lengths that were stable over 120 cell divisions. These stable chromosome specific telomere lengths may be explained by stochastic clonal variation or may represent a new biological mechanism that maintains equilibrium unique to each chromosomes end. We examined the role of RIF1 and TEL1 in telomere length regulation and found that TEL1 is epistatic to RIF1 at most telomeres, consistent with the literature. However, at telomeres that lack subtelomeric Y' sequences, tel1Δ rif1Δ double mutants had a very small, but significant, increase in telomere length compared to the tel1Δ single mutant, suggesting an influence of Y' elements on telomere length regulation. We sequenced telomeres in a telomerase-null mutant (est2Δ) and found the minimal telomere length to be around 75bp. In these est2Δ mutants there were many apparent telomere recombination events at individual telomeres before the generation of survivors, and these events were significantly reduced in est2Δ rad52Δ double mutants. The rate of telomere shortening in the absence of telomerase was similar across all chromosome ends at about 5 bp per generation. This new method gives quantitative, high resolution telomere length measurement at each individual chromosome end, suggests possible new biological mechanisms regulating telomere length, and provides capability to test new hypotheses.

scholarly journals Antagonistic selection on body size and sword length in a wild population of the swordtail fish, Xiphophorus multilineatus: potential for intralocus tactical conflict

2021 ◽  
Author(s):  
Melissa Liotta ◽  
Jessica Abbott ◽  
Molly Morris ◽  
Oscar Rios-Cardenas
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Wild Population ◽  
Genetic Correlations ◽  
Reproductive Tactics ◽  
Swordtail Fish ◽  
The Arts ◽  
In The Wild ◽  
Life History Tradeoffs

Alternative reproductive tactics (ARTs) have provided valuable insights into how sexual selection and life history tradeoffs can lead to variation within a sex. However, the possibility that tactics may constrain evolution through intralocus tactical conflict (IATC) is rarely considered. In addition, when IATC has been considered, the focus has often been on the genetic correlations between the ARTs, while evidence that the ARTs have different optima for associated traits and that at least one of the tactics is not at its optima is often missing. Here we investigate selection on three traits associated with the ARTs in the swordtail fish Xiphophorus multilineatus; body size, body shape and the sexually selected trait for which these fishes were named, sword length (elongation of the caudal fin). All three traits are tactically dimorphic, with courter males being larger, deeper bodied and having longer swords, and the sneaker males being smaller, more fusiform and having shorter swords. Using measures of reproductive success in a wild population we calculated selection differentials, linear and quadratic gradients, demonstrate that the tactics have different optima and at least one of the tactics is not at its optima for body size and sword length. Our results provide the first evidence of selection in the wild on the sword, an iconic trait for sexual selection. In addition, given the high probability that these traits are genetically correlated to some extent between the two tactics, our study suggests that IATC is constraining both body size and the sword from reaching their phenotypic optima. We discuss the importance of considering the role of IATC in the evolution of tactical dimorphism, how this conflict can be present despite tactical dimorphism, and how it is important to consider this conflict when explaining not only variation within a species but differences across species as well.

The Possible Role of Telomere Length and Chemokines in the Aging Process: A Transdiagnostic Review in Psychiatry

2019 ◽  
Vol 15 (3) ◽  
pp. 171-192
Author(s):  
Fernanda Endler Valiati ◽  
Gabriel Henrique Hizo ◽  
Jairo Vinícius Pinto ◽  
Márcia Kauer-Sant`Anna
Keyword(s):  
Psychiatric Disorders ◽  
Telomere Length ◽  
Aging Process ◽  
Accelerated Aging ◽  
Premature Death ◽  
Mental Illnesses ◽  
Telomere Shortening ◽  
Early Aging ◽  
The Relationship

Background: Psychiatric disorders are common, reaching a worldwide prevalence of 29.2%. They are associated with a high risk of premature death and with accelerated aging in clinical, molecular and neuroimaging studies. Recently, there is strong evidence suggesting a possible role of telomere length and chemokines in aging processes in psychiatric disorders. Objective: We aimed to review the literature on telomere length and chemokines and its association with early aging in mental illnesses on a transdiagnostic approach. Results: The review highlights the association between psychiatric disorders and early aging. Several independent studies have reported shorter telomere length and dysregulations on levels of circulating chemokines in schizophrenia, bipolar disorder, major depressive disorder, and anxiety disorders, suggesting a complex interaction between these markers in a transdiagnostic level. However, studies have investigated the inflammatory markers and telomere shortening separately and associated with a particular diagnosis, rather than as a transdiagnostic biological feature. Conclusion: There is consistent evidence supporting the relationship between accelerated aging, telomere length, and chemokines in mental disorders, but they have been studied individually. Thus, more research is needed to improve the knowledge of accelerated senescence and its biomarkers in psychiatry, not only individually in each diagnosis, but also based on a transdiagnostic perspective. Moreover, further research should try to elucidate how the intricate association between the chemokines and telomeres together may contribute to the aging process in psychiatric disorders.

scholarly journals Telomeres and telomerase as therapeutic targets to prevent and treat age-related diseases

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 89 ◽  
Author(s):  
Christian Bär ◽  
Maria A. Blasco
Keyword(s):  
Environmental Factors ◽  
Telomere Length ◽  
Therapeutic Targets ◽  
Therapeutic Strategies ◽  
Telomere Shortening ◽  
Age Related ◽  
Human Telomere ◽  
Linear Chromosomes ◽  
Telomere Erosion

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual’s lifetime. Telomere shortening is a hallmark of molecular aging and is associated with premature appearance of diseases associated with aging. Here, we discuss the role of telomere shortening as a direct cause for aging and age-related diseases. In particular, we draw attention to the fact that telomere length influences longevity. Furthermore, we discuss intrinsic and environmental factors that can impact on human telomere erosion. Finally, we highlight recent advances in telomerase-based therapeutic strategies for the treatment of diseases associated with extremely short telomeres owing to mutations in telomerase, as well as age-related diseases, and ultimately aging itself.

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