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1. Sex Differences in Telomere Length in a Bat With Female‐Biased Longevity

   https://doi.org/10.1002/ece3.71378  

   Rayner, Jack_G; Marshall, Abigail; Adams, Danielle_M; Kaiser, Jillian; Armenta, Katherine; Wilkinson, Gerald_S (May 2025, Ecology and Evolution)

   ABSTRACT Telomeres, protective caps at the ends of linear chromosomes, are frequently found to shorten with age. Telomere length is commonly measured in wild populations to investigate age‐related changes in somatic integrity and is considered a hallmark of ageing. Despite interest, there is no clear picture regarding sex differences in telomere length or rate of attrition across species. Bats are of considerable interest in studies of ageing and telomeres, owing to their remarkable longevity and the absence of age‐associated telomere attrition observed in some species. Additionally, multiple bat species show evidence of sex differences in longevity. However, few studies of bat telomeres have included both sexes. We collected DNA from wild‐caught males and females of the highly polygynous greater spear‐nosed bat,Phyllostomus hastatus, in which mortality is strongly male‐biased, and measured relative telomere lengths. We found that, while telomeres were shorter in older bats, there was no evidence of shorter telomeres in males. In fact, males tended to have longer telomeres. This runs counter to our prediction of shorter telomeres in the shorter‐lived sex but is not completely unexpected in light of other observations, including that of shorter telomeres in longer lived species. 

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2. Parental age does not influence offspring telomeres during early life in common gulls (Larus canus)

   https://doi.org/DOI: 10.1111/mec.15905  

   Sepp, T.; Meitern, R; Heidinger, B.; Noreikiene, K.; Rattiste, K.; Horak, P.; Saks, L.; Kittilson, J.; Urvik, J.; Giraudeau, M. (January 2021, Molecular ecology)

   null (Ed.)

   Parental age can affect offspring telomere length through heritable and epigenetic-like effects, but at what stage during development these effects are established is not well known. To address this, we conducted a cross-fostering experiment in common gulls (Larus canus) that enabled us distinguish between pre-and post-natal parental age effects on offspring telomere length. Whole clutches were exchanged after clutch completion within and between parental age classes (young and old) and blood samples were collected from chicks at hatching and during the fastest growth phase (11 days later) to measure telomeres. Neither the ages of the natal nor the foster parents predicted the telomere length or the change in telomere lengths of their chicks. Telomere length (TL) was repeatable within chicks, but increased across development (repeatability = 0.55, intraclass correlation coefficient within sampling events 0.934). Telomere length and the change in telomere length were not predicted by post-natal growth rate. Taken together, these findings suggest that in common gulls, telomere length during early life is not influenced by parental age or growth rate, which may indicate that protective mechanisms buffer telomeres from external conditions during development in this relatively long-lived species. 

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3. Primers to highly conserved elements optimized for qPCR‐based telomere length measurement in vertebrates

   https://doi.org/10.1111/1755-0998.13238  

   Hudon, Stephanie F.; Palencia Hurtado, Esteban; Beck, James D.; Burden, Steven J.; Bendixsen, Devin P.; Callery, Kathleen R.; Sorensen Forbey, Jennifer; Waits, Lisette P.; Miller, Robert A.; Nielsen, Ólafur K.; et al (August 2020, Molecular Ecology Resources)

   Abstract Telomere length dynamics are an established biomarker of health and ageing in animals. The study of telomeres in numerous species has been facilitated by methods to measure telomere length by real‐time quantitative PCR (qPCR). In this method, telomere length is determined by quantifying the amount of telomeric DNA repeats in a sample and normalizing this to the total amount of genomic DNA. This normalization requires the development of genomic reference primers suitable for qPCR, which remains challenging in nonmodel organism with genomes that have not been sequenced. Here we report reference primers that can be used in qPCR to measure telomere lengths in any vertebrate species. We designed primer pairs to amplify genetic elements that are highly conserved between evolutionarily distant taxa and tested them in species that span the vertebrate tree of life. We report five primer pairs that meet the specificity and reproducibility standards of qPCR. In addition, we demonstrate an approach to choose the best primers for a given species by testing the primers on multiple individuals within a species and then applying an established computational tool. These reference primers can facilitate qPCR‐based telomere length measurements in any vertebrate species of ecological or economic interest. 

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4. Early‐breeding females experience greater telomere loss

   https://doi.org/10.1111/mec.14952  

   Graham, Jessica L.; Bauer, Carolyn M.; Heidinger, Britt J.; Ketterson, Ellen D.; Greives, Timothy J. (January 2019, Molecular Ecology)

   Abstract Annual reproductive success is often highest in individuals that initiate breeding early, yet relatively few individuals start breeding during this apparently optimal time. This suggests that individuals, particularly females who ultimately dictate when offspring are born, incur costs by initiating reproduction early in the season. We hypothesized that increases in the ageing rate of somatic cells may be one such cost. Telomeres, the repetitive DNA sequences on the ends of chromosomes, may be good proxies of biological wear and tear as they shorten with age and in response to stress. Using historical data from a long‐term study population of dark‐eyed juncos (Junco hyemalis), we found that telomere loss between years was greater in earlier breeding females, regardless of chronological age. There was no relationship between telomere loss and the annual number of eggs laid or chicks that reached independence. However, telomere loss was greater when temperatures were cooler, and cooler temperatures generally occur early in the season. This suggests that environmental conditions could be the primary cause of accelerated telomere loss in early breeders. 

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5. No evidence of physiological declines with age in an extremely long-lived fish

   https://doi.org/10.1038/s41598-021-88626-5  

   Sauer, Derek J.; Heidinger, Britt J.; Kittilson, Jeffrey D.; Lackmann, Alec R.; Clark, Mark E. (December 2021, Scientific Reports)

   null (Ed.)

   Abstract Although the pace of senescence varies considerably, the physiological systems that contribute to different patterns of senescence are not well understood, especially in long-lived vertebrates. Long-lived bony fish (i.e., Class Osteichthyes) are a particularly useful model for studies of senescence because they can readily be aged and exhibit some of the longest lifespans among vertebrates. In this study we examined the potential relationship between age and multiple physiological systems including: stress levels, immune function, and telomere length in individuals ranging in age from 2 to 99 years old in bigmouth buffalo ( Ictiobus cyprinellus ), the oldest known freshwater teleost fish. Contrary to expectation, we did not find any evidence for age-related declines in these physiological systems. Instead, older fish appeared to be less stressed and had greater immunity than younger fish, suggesting age-related improvements rather than declines in these systems. There was no significant effect of age on telomeres, but individuals that may be more stressed had shorter telomeres. Taken together, these findings suggest that bigmouth buffalo exhibit negligible senescence in multiple physiological systems despite living for nearly a century. 

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