scholarly journals Telomere shortening as a mechanism of long-term cost of infectious diseases in natural animal populations

2019 ◽  
Vol 15 (5) ◽  
pp. 20190190 ◽  
Author(s):  
Mathieu Giraudeau ◽  
Britt Heidinger ◽  
Camille Bonneaud ◽  
Tuul Sepp
Keyword(s):  
Telomere Maintenance ◽  
Laboratory Animals ◽  
Experimental Investigations ◽  
Telomere Shortening ◽  
Animal Populations ◽  
In The Wild ◽  
Selective Forces ◽  
Long Term Impact ◽  
Telomere Erosion

Pathogens are potent selective forces that can reduce the fitness of their hosts. While studies of the short-term energetic costs of infections are accumulating, the long-term costs have only just started to be investigated. Such delayed costs may, at least in part, be mediated by telomere erosion. This hypothesis is supported by experimental investigations conducted on laboratory animals which show that infection accelerates telomere erosion in immune cells. However, the generalizability of such findings to natural animal populations and to humans remains debatable. First, laboratory animals typically display long telomeres relative to their wild counterparts. Second, unlike humans and most wild animals, laboratory small-bodied mammals are capable of telomerase-based telomere maintenance throughout life. Third, the effect of infections on telomere shortening and ageing has only been studied using single pathogen infections, yet hosts are often simultaneously confronted with a range of pathogens in the wild. Thus, the cost of an infection in terms of telomere-shortening-related ageing in natural animal populations is likely to be strongly underestimated. Here, we discuss how investigations into the links between infection, immune response and tissue ageing are now required to improve our understanding of the long-term impact of disease.

scholarly journals Impact of continuous predator threat on telomere dynamics in parent and nestling pied flycatchers

Oecologia ◽  
2019 ◽  
Vol 191 (4) ◽  
pp. 757-766 ◽  
Author(s):  
Tiia Kärkkäinen ◽  
Pauliina Teerikorpi ◽  
Bineet Panda ◽  
Samuli Helle ◽  
Antoine Stier ◽  
...  
Keyword(s):  
Predation Risk ◽  
Telomere Maintenance ◽  
Stress Hormone ◽  
Ageing Rate ◽  
In The Wild ◽  
Males And Females ◽  
Perceived Predation Risk ◽  
Telomere Dynamics ◽  
Predator Threat

Abstract In addition to direct mortality, predators can have indirect effects on prey populations by affecting prey behaviour or physiology. For example, predator presence can increase stress hormone levels, which can have physiological costs. Stress exposure accelerates the shortening of telomeres (i.e. the protective caps of chromosomes) and shorter telomeres have been linked to increased mortality risk. However, the effect of perceived predation risk on telomeres is not known. We investigated the effects of continuous predator threat (nesting Eurasian pygmy owl Glaucidium passerinum) on telomere dynamics of both adult and partially cross-fostered nestling pied flycatchers (Ficedula hypoleuca) in the wild. Females nesting at owl-inhabited sites showed impaired telomere maintenance between incubation and chick rearing compared to controls, and both males and females ended up with shorter telomeres at owl-inhabited sites in the end of chick rearing. On the contrary, both original and cross-fostered chicks reared in owl sites had consistently longer telomeres during growth than chicks reared at control sites. Thus, predation risk may cause a long-term cost in terms of telomeres for parents but not for their offspring. Predators may therefore affect telomere dynamics of their preys, which could have implications for their ageing rate and consequently for population dynamics.

scholarly journals Replicative senescence dictates the emergence of disease-associated microglia and contributes to Aβ pathology

2021 ◽  
Author(s):  
Yanling Hu ◽  
Gemma L. Fryatt ◽  
Mohammadmersad Ghorbani ◽  
Juliane Obst ◽  
David A. Menassa ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Replicative Senescence ◽  
Post Mortem ◽  
Telomere Shortening ◽  
Transcriptional Signature ◽  
Microglial Proliferation ◽  
Long Term Impact ◽  
Repeated Cycling

ABSTRACTThe sustained proliferation of microglia is a key hallmark of Alzheimer’s disease (AD), accelerating its progression. Here, we sought to understand the long-term impact of the early and prolonged microglial proliferation observed in AD, hypothesising that extensive and repeated cycling would engender a distinct transcriptional and phenotypic trajectory. We found that the early and sustained microglial proliferation seen in an AD-like model promotes replicative senescence, characterised by increased βgal activity, a senescence-associated transcriptional signature and telomere shortening, correlating with the appearance of disease-associated microglia (DAM) and senescent microglial profiles in human post-mortem AD cases. Prevention of early microglial proliferation hindered the development of senescence and DAM, impairing the accumulation of Aβ and associated neuritic damage. Overall, our results support that excessive microglial proliferation leads to the generation of senescent DAM, which contribute to early Aβ pathology in AD.

scholarly journals Gene flow between introduced and native Eucalyptus species: exotic hybrids are establishing in the wild

2003 ◽  
Vol 51 (4) ◽  
pp. 429 ◽  
Author(s):  
R. C. Barbour ◽  
B. M. Potts ◽  
R. E. Vaillancourt
Keyword(s):  
Gene Flow ◽  
Native Species ◽  
Parental Species ◽  
F1 Hybrids ◽  
Eucalyptus Species ◽  
Eucalyptus Nitens ◽  
Natural Hybrids ◽  
In The Wild ◽  
Long Term Impact

F1 hybrids between exotic Eucalyptus nitens plantations and native E. ovata have previously been reported among seedlings grown from open-pollinated seed collected from E. ovata, on the island of Tasmania. Such exotic hybrid seedlings have now been found in the wild adjacent to plantations at three locations. The proportion of exotic hybrids in open-pollinated seed collected from nearby mature E. ovata was 5.5%. This level compares with only 0.4% for natural hybrids between native species at these sites (E. ovata, E. viminalis and E.�rodwayi). Detection of hybrids was initially based on their deviant morphology, which was generally intermediate between parental species. This subjective classification was then successfully verified by morphometric and allozyme analyses. Pure E. nitens seedlings (wildlings) were restricted to within 30 m of these plantations, whereas established hybrids were found up to 310 m from the plantations. This pattern of establishment reflects dispersal of exotic seed and pollen respectively. It is likely that the recent expansion of the eucalypt plantation estate in Australia will cause an increase in the frequency of exotic hybrids. However, the long-term impact of such hybridisation is yet to be assessed.

scholarly journals Evolution of quantitative traits in the wild: mind the ecology

2010 ◽  
Vol 365 (1552) ◽  
pp. 2431-2438 ◽  
Author(s):  
Josephine M. Pemberton
Keyword(s):  
Quantitative Genetics ◽  
Quantitative Traits ◽  
Natural Populations ◽  
Response To Selection ◽  
Genetic Response ◽  
Quantitative Genetic ◽  
Animal Populations ◽  
In The Wild ◽  
Gradient Variation

Recent advances in the quantitative genetics of traits in wild animal populations have created new interest in whether natural selection, and genetic response to it, can be detected within long-term ecological studies. However, such studies have re-emphasized the fact that ecological heterogeneity can confound our ability to infer selection on genetic variation and detect a population's response to selection by conventional quantitative genetics approaches. Here, I highlight three manifestations of this issue: counter gradient variation, environmentally induced covariance between traits and the correlated effects of a fluctuating environment. These effects are symptomatic of the oversimplifications and strong assumptions of the breeder's equation when it is applied to natural populations. In addition, methods to assay genetic change in quantitative traits have overestimated the precision with which change can be measured. In the future, a more conservative approach to inferring quantitative genetic response to selection, or genomic approaches allowing the estimation of selection intensity and responses to selection at known quantitative trait loci, will provide a more precise view of evolution in ecological time.

Seeding small numbers of cultured black-lip abalone (Haliotis rubra Leach) to match natural densities of wild populations

2006 ◽  
Vol 57 (7) ◽  
pp. 747 ◽  
Author(s):  
P. J. Goodsell ◽  
A. J. Underwood ◽  
M. G. Chapman ◽  
M. P. Heasman
Keyword(s):  
Experimental Investigations ◽  
Commercial Fishing ◽  
Wild Populations ◽  
Natural Habitats ◽  
Term Survival ◽  
Total Recovery ◽  
Density Dependent ◽  
In The Wild ◽  
Haliotis Rubra

Haliotis rubra Leach, the black-lip abalone, is a valuable, commercially harvested species, but populations have declined since the onset of commercial fishing. Seeding juvenile cultured abalone into natural habitats can enhance and/or re-establish populations. This is often done in numbers well above natural densities of both unfished and fished populations, but is usually unsuccessful (probably because of increased mortality from predation or other density-dependent factors) and is potentially problematic for the ecology of the habitat. A major aim was, therefore, to assess survival of H. rubra when seeded in small numbers. The current study is one of a few experimental investigations to improve understanding of the potential of re-seeding. We test: (1) the importance of the spatial and temporal configuration of seed; (2) the usefulness of the urchins, Centroste phanus rodgersii, to act as a potential shelter from predators; and (3) differences in survival when using the deployment devices versus urchins. After a few days, total recovery among treatments ranged between 3 and 31%. The configuration of abalone or their proximity to urchins did not affect long-term survival. Survival in devices may be greater than with urchins, but these results were spatially variable. Recovery dropped to 0.2–3% from 1–2 months, and 0.05–2% after 6 months. Nevertheless, these results show that seeding fewer abalone (rather than previous attempts at mass out-planting) can sustain populations close to average natural densities of adults previously observed in Australia (1–3 abalone per m2). It may be more productive and ecologically conservative to release fewer and therefore larger abalone, which are known to survive better in the wild.

Crisis Phones - Suicide Prevention Versus Suggestion/Contagion Effects

Crisis ◽  
2015 ◽  
Vol 36 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Steven Stack
Keyword(s):  
Suicide Prevention ◽  
Contagion Effects ◽  
Long Term Impact

Abstract. Background: There has been no systematic work on the short- or long-term impact of the installation of crisis phones on suicides from bridges. The present study addresses this issue. Method: Data refer to 219 suicides from 1954 through 2013 on the Skyway Bridge in St. Petersburg, Florida. Six crisis phones with signs were installed in July 1999. Results: In the first decade after installation, the phones were used by 27 suicidal persons and credited with preventing 26 or 2.6 suicides a year. However, the net suicide count increased from 48 in the 13 years before installation of phones to 106 the following 13 years or by 4.5 additional suicides/year (t =3.512, p < .001). Conclusion: Although the phones prevented some suicides, there was a net increase after installation. The findings are interpreted with reference to suggestion/contagion effects including the emergence of a controversial bridge suicide blog.

Long-Term Impact of Participation in the Adolescent Diversion Project

2009 ◽  
Author(s):  
Jenna L. Claes ◽  
Sean S. Hankins ◽  
J. K. Ford
Keyword(s):  
Long Term Impact

Anesthesia for rabbits submitted to experimental surgeries: Report of a series of eight anesthesias

2020 ◽  
pp. 151-158
Author(s):  
Rafael Antonio Caldart Bedin ◽  
Maisa Schultz ◽  
Antonio Bedin
Keyword(s):  
Muscle Relaxation ◽  
Anesthetic Management ◽  
Laboratory Animals ◽  
Average Weight ◽  
Anesthetic Induction ◽  
Anesthetic Agents ◽  
Reasonable Degree ◽  
Bioethical Debate ◽  
Precordial Stethoscope

Anesthesia for laboratory animals is a matter of biomedical concern and one of the most present dilemmas in the current bioethical debate. The use of anesthetic agents in experimental surgery aims at analgesia and restraining the animal, in order to achieve a reasonable degree of muscle relaxation and to produce sufficient analgesia. This practice requires the use of protocols for the administration of safe and efficient doses. Eight New Zealand rabbits were submitted to laparotomies demonstrating the surgical technique discipline of the local medical course. For pre-anesthetic medication, acepromazine 1 mg.kg-1 associated with ketamine 15 mg.kg-1 was used subcutaneously. Anesthesia was maintained with isoflurane and oxygen under a laryngeal mask in a Mapleson D anesthesia system and under spontaneous breathing. Hydration was performed with 10 ml.kg-1 saline every hour. A thermal mattress was used. Precordial stethoscope, pulse oximetry and clinical parameters were used for monitoring. For euthanasia, ketamine 10 mg.kg-1 associated with potassium chloride 19.1% 1 ml.kg-1 was used intravenously. The average weight of the rabbits was 2721.25 ± 275.01 grams and the duration of the anesthetic procedure was 120 ± 87 minutes. Discussion. In long-term anesthesia, such as laparotomies, the use of pre-anesthetic medication and then anesthetic induction by the combination of agents is recommended. However, anesthetic management requires monitoring to prevent insufficient or excessive doses from occurring.

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