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Negligible senescence

Siegfried Zerche, Klaus-Thomas Haensch, Uwe Druege, Mohammad-Reza Hajirezaei
BACKGROUND: Adventitious root (AR) formation in axillary shoot tip cuttings is a crucial physiological process for ornamental propagation that is utilised in global production chains for young plants. In this process, the nitrogen and carbohydrate metabolisms of a cutting are regulated by its total nitrogen content (Nt), dark exposure during transport and irradiance levels at distinct production sites and phases through a specific plasticity to readjust metabolite pools. Here, we examined how elevated Nt contents with a combined dark exposure of cuttings influence their internal N-pools including free amino acids and considered early anatomic events of AR formation as well as further root development in Petunia hybrida cuttings...
October 10, 2016: BMC Plant Biology
Jácint Tökölyi, Zsófia Ősz, Flóra Sebestyén, Zoltán Barta
Freshwater hydra are among the few animal groups that show negligible senescence and can maintain high survival and reproduction rates when kept under stable conditions in the laboratory. Yet, one species of Hydra (H. oligactis) undergoes a senescence-like process in which polyps degenerate and die after sexual reproduction. The ultimate factors responsible for this phenomenon are unclear. High mortality in reproducing animals could be the consequence of increased allocation of resources to reproduction at the expense of somatic maintenance...
June 23, 2016: Zoology: Analysis of Complex Systems, ZACS
Junpei Yamanashi, Hideko Takayanagi, Ayaka Isaji, Ryuji Asami, Yasufumi Iryu
We report the carbon (δ13C) and oxygen (δ18O) isotope records of three modern Tridacna derasa shells from Ishigaki-jima, southwestern Japan. The high-resolution δ13C profiles of samples from the inner shell layer on cross-sections fall within similar narrow ranges and display no regular variations or trends, such as an ontogenetic trend or abrupt short-term drops likely to be related to reproductive activity. This suggests that the calcification site of this species is not likely affected by photosynthetic CO2 uptake or CO2 incorporation during respiration...
2016: PloS One
Daniel A Warner, David A W Miller, Anne M Bronikowski, Fredric J Janzen
Lifespan and aging rates vary considerably across taxa; thus, understanding the factors that lead to this variation is a primary goal in biology and has ramifications for understanding constraints and flexibility in human aging. Theory predicts that senescence-declining reproduction and increasing mortality with advancing age-evolves when selection against harmful mutations is weaker at old ages relative to young ages or when selection favors pleiotropic alleles with beneficial effects early in life despite late-life costs...
June 7, 2016: Proceedings of the National Academy of Sciences of the United States of America
Andrea G Bodnar, James A Coffman
Aging in many animals is characterized by a failure to maintain tissue homeostasis and the loss of regenerative capacity. In this study, the ability to maintain tissue homeostasis and regenerative potential was investigated in sea urchins, a novel model to study longevity and negligible senescence. Sea urchins grow indeterminately, regenerate damaged appendages and reproduce throughout their lifespan and yet different species are reported to have very different life expectancies (ranging from 4 to more than 100 years)...
August 2016: Aging Cell
Kaori Oka, Kyoko Miura
No abstract text is available yet for this article.
February 2016: Seikagaku. the Journal of Japanese Biochemical Society
Alessandra Lucioli, Carlo Perla, Alessandra Berardi, Francesca Gatti, Laura Spanò, Mario Tavazza
To establish a successful infection viruses need to overcome plant innate immune responses and redirect host gene expression for their multiplication and diffusion. Tomato yellow leaf curl Sardinia virus (TYLCSV) is a geminivirus, which causes significant economic losses in tomato. The multifunctional replication associated geminivirus protein (Rep) has an important role during viral infection. In particular, the Rep central domain spanning from aa 120 to 180 is known to interact with viral and host factors...
June 2016: Plant Physiology and Biochemistry: PPB
Judy C Triplett, Aaron M Swomley, Jessime Kirk, Kelly M Grimes, Kaitilyn N Lewis, Miranda E Orr, Karl A Rodriguez, Jian Cai, Jon B Klein, Rochelle Buffenstein, D Allan Butterfield
Aging is the greatest risk factor for developing neurodegenerative diseases, which are associated with diminished neurotransmission as well as neuronal structure and function. However, several traits seemingly evolved to avert or delay age-related deterioration in the brain of the longest-lived rodent, the naked mole-rat (NMR). The NMR remarkably also exhibits negligible senescence, maintaining an extended healthspan for ~75 % of its life span. Using a proteomic approach, statistically significant changes with age in expression and/or phosphorylation levels of proteins associated with neurite outgrowth and neurotransmission were identified in the brain of the NMR and include: cofilin-1; collapsin response mediator protein 2; actin depolymerizing factor; spectrin alpha chain; septin-7; syntaxin-binding protein 1; synapsin-2 isoform IIB; and dynamin 1...
July 2016: Neurochemical Research
Lucie Kučerová, Olga I Kubrak, Jonas M Bengtsson, Hynek Strnad, Sören Nylin, Ulrich Theopold, Dick R Nässel
BACKGROUND: In models extensively used in studies of aging and extended lifespan, such as C. elegans and Drosophila, adult senescence is regulated by gene networks that are likely to be similar to ones that underlie lifespan extension during dormancy. These include the evolutionarily conserved insulin/IGF, TOR and germ line-signaling pathways. Dormancy, also known as dauer stage in the larval worm or adult diapause in the fly, is triggered by adverse environmental conditions, and results in drastically extended lifespan with negligible senescence...
2016: BMC Genomics
Malene Brohus, Vera Gorbunova, Chris G Faulkes, Michael T Overgaard, Cheryl A Conover
Naked mole-rats (Heterocephalus glaber) (NMRs) are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs) have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells...
2015: PloS One
Sergi Munné-Bosch
Both demographic and physiological senescence have been demonstrated to occur in various organisms. However, indeterminate growers, such as some animals and most perennial plants, seem to escape the wear and tear of aging. Indeed, most angiosperms show no signs of senescence, and both negligible and negative senescence (improved physiological performance with aging) have been reported in perennial plants growing in their natural habitat. In this opinion article, I review recent developments in the study of senescence in perennial plants and propose that continuous growth prevents senescence...
November 2015: Trends in Plant Science
Micael Reis, Felipe B Valer, Cristina P Vieira, Jorge Vieira
Diapause is a period of arrested development which is controlled physiologically, preprogrammed environmentally and characterized by metabolic depression that can occur during any stage of insect development. Nevertheless, in the genus Drosophila, diapause is almost always associated with the cessation of ovarian development and reproductive activity in adult females. In this work, we show that, in D. americana (a temperate species of the virilis group), diapause is a genetically determined delay in ovarian development that is triggered by temperature and/or photoperiod...
2015: PloS One
Valeria Kogan, Ivan Molodtsov, Leonid I Menshikov, Robert J Shmookler Reis, Peter Fedichev
Several animal species are considered to exhibit what is called negligible senescence, i.e. they do not show signs of functional decline or any increase of mortality with age. Recent studies in naked mole rat and long-lived sea urchins showed that these species do not alter their gene-expression profiles with age as much as other organisms do. This is consistent with exceptional endurance of naked mole rat tissues to various genotoxic stresses. We conjectured, therefore, that the lifelong transcriptional stability of an organism may be a key determinant of longevity...
2015: Scientific Reports
Axel Kowald, Thomas B L Kirkwood
Human lifespan has risen dramatically over the last 150 years, leading to a significant increase in the fraction of aged people in the population. Until recently it was believed that this contrasted strongly with the situation in wild populations of animals, where the likelihood of encountering demonstrably senescent individuals was believed to be negligible. Over the recent years, however, a series of field studies has appeared that shows ageing can also be observed for many species in the wild. We discuss here the relevance of this finding for the different evolutionary theories of ageing, since it has been claimed that ageing in the wild is incompatible with the so-called non-adaptive (non-programmed) theories, i...
November 2015: Experimental Gerontology
Judy C Triplett, Antonella Tramutola, Aaron Swomley, Jessime Kirk, Kelly Grimes, Kaitilyn Lewis, Miranda Orr, Karl Rodriguez, Jian Cai, Jon B Klein, Marzia Perluigi, Rochelle Buffenstein, D Allan Butterfield
The naked mole-rat (NMR) is the longest-lived rodent and possesses several exceptional traits: marked cancer resistance, negligible senescence, prolonged genomic integrity, pronounced proteostasis, and a sustained health span. The underlying molecular mechanisms that contribute to these extraordinary attributes are currently under investigation to gain insights that may conceivably promote and extend human health span and lifespan. The ubiquitin-proteasome and autophagy-lysosomal systems play a vital role in eliminating cellular detritus to maintain proteostasis and have been previously shown to be more robust in NMRs when compared with shorter-lived rodents...
October 2015: Biochimica et Biophysica Acta
E Novikov, E Kondratyuk, D Petrovski, T Titova, I Zadubrovskaya, P Zadubrovskiy, M Moshkin
Eusocial subterranean rodents of the Bathyergidae family have enormous longevity. The long lifespan of these species is associated with negligible senescence, that is, an absence of the signs of age-related deterioration in physical condition. The question arises as to whether these features are unique to eusocial Bathyergids or typical of other social subterranean rodents as well. In the present study, we analysed data from observations of a social subterranean Microtinae rodent, the northern mole vole (Ellobius talpinus Pall...
December 2015: Biogerontology
Andrea G Bodnar
Sea urchins exhibit a very different life history from humans and short-lived model animals and therefore provide the opportunity to gain new insight into the complex process of aging. Sea urchins grow indeterminately, regenerate damaged appendages, and reproduce throughout their lifespan. Some species show no increase in mortality rate at advanced ages. Nevertheless, different species of sea urchins have very different reported lifespans ranging from 4 to more than 100 years, thus providing a unique model to investigate the molecular, cellular, and physiological mechanisms underlying both lifespan determination and negligible senescence...
January 30, 2015: Invertebrate Reproduction & Development
Marios Kyriazis, Andreas Apostolides
The process of aging is a continuum of degeneration which eventually leads to loss of function and clinically manifest disease. Yet, in the purely therapeutic sense, there is a distinct clinical and practical separation between age-related degenerative diseases and the background process of aging itself. It is quite possible that biomedical technologies will prove invaluable in treating or alleviating the impact of distinct age-related degenerative diseases such as cardiovascular disease, arthritis or dementia...
2015: Current Aging Science
Joseph P Salisbury, Ruxandra F Sîrbulescu, Benjamin M Moran, Jared R Auclair, Günther K H Zupanc, Jeffrey N Agar
BACKGROUND: The brown ghost knifefish (Apteronotus leptorhynchus) is a weakly electric teleost fish of particular interest as a versatile model system for a variety of research areas in neuroscience and biology. The comprehensive information available on the neurophysiology and neuroanatomy of this organism has enabled significant advances in such areas as the study of the neural basis of behavior, the development of adult-born neurons in the central nervous system and their involvement in the regeneration of nervous tissue, as well as brain aging and senescence...
2015: BMC Genomics
Oge Arum, Jamal Saleh, Ravneet Boparai, Jeremy Turner, John Kopchick, Romesh Khardori, Andrzej Bartke
The correlation of physiological sensitivity to insulin ( vis-à-vis glycemic regulation) and longevity is extensively established, creating a justifiable gerontological interest on whether insulin sensitivity is causative, or even predictive, of some or all phenotypes of slowed senescence (including longevity). The growth hormone receptor/ binding protein gene-disrupted (GHR-KO) mouse is the most extensively investigated insulin-sensitive, attenuated aging model. It was reported that, in a manner divergent from similar mutants, GHR-KO mice fail to respond to caloric restriction (CR) by altering their insulin sensitivity...
2014: F1000Research
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