Studies on human telomeres have established that telomeres exert a significant influence on lifespan and health of organisms. However, recent research has indicated that the original idea that telomeres affect lifespan in a universal and central manner across all eukaryotic species is an oversimplification. Indeed, findings from a variety of animal species revealed that the role of telomere biology in aging is more subtle and intricate than previously recognized. Here, we show how telomere biology varies depending on the taxon. We also show how telomere biology corresponds to basic life history traits and affects the life table of a species and investments in growth, body size, reproduction, and lifespan; telomeres are hypothesized to shape evolutionary perspectives for species in an active but complex manner. Our evaluation is based on telomere biology data from many examples from throughout the animal kingdom that vary according to the degree of organismal complexity and life history strategies.
- Klíčová slova
- Aging, Life history traits, Lifespan, Telomerase, Telomeres,
- MeSH
- biologická evoluce MeSH
- dlouhověkost MeSH
- lidé MeSH
- stárnutí genetika MeSH
- telomerasa * genetika MeSH
- telomery MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- telomerasa * MeSH
In contrast to the catalytic subunit of telomerase, its RNA subunit (TR) is highly divergent in size, sequence and biogenesis pathways across eukaryotes. Current views on TR evolution assume a common origin of TRs transcribed with RNA polymerase II in Opisthokonta (the supergroup including Animalia and Fungi) and Trypanosomida on one hand, and TRs transcribed with RNA polymerase III under the control of type 3 promoter, found in TSAR and Archaeplastida supergroups (including e.g. ciliates and Viridiplantae taxa, respectively). Here, we focus on unknown TRs in one of the largest Animalia order - Hymenoptera (Arthropoda) with more than 300 available representative genomes. Using a combination of bioinformatic and experimental approaches, we identify their TRs. In contrast to the presumed type of TRs (H/ACA box snoRNAs transcribed with RNA Polymerase II) corresponding to their phylogenetic position, we find here short TRs of the snRNA type, likely transcribed with RNA polymerase III under the control of the type 3 promoter. The newly described insect TRs thus question the hitherto assumed monophyletic origin of TRs across Animalia and point to an evolutionary switch in TR type and biogenesis that was associated with the divergence of Arthropods.
- MeSH
- Eukaryota genetika MeSH
- fylogeneze MeSH
- Hymenoptera * genetika MeSH
- konformace nukleové kyseliny MeSH
- RNA-polymerasa II genetika metabolismus MeSH
- RNA-polymerasa III genetika metabolismus MeSH
- RNA genetika MeSH
- rostliny genetika MeSH
- telomerasa * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- RNA-polymerasa II MeSH
- RNA-polymerasa III MeSH
- RNA MeSH
- telomerasa * MeSH
- telomerase RNA MeSH Prohlížeč
Telomeres in Drosophila melanogaster, which have inspired a large part of Sergio Pimpinelli work, are similar to those of other eukaryotes in terms of their function. Yet, their length maintenance relies on the transposition of the specialized retrotransposons Het-A, TART, and TAHRE, rather than on the activity of the enzyme telomerase as it occurs in most other eukaryotic organisms. The length of the telomeres in Drosophila thus depends on the number of copies of these transposable elements. Our previous work has led to the isolation of a dominant mutation, Tel1, that caused a several-fold elongation of telomeres. In this study, we molecularly identified the Tel1 mutation by a combination of transposon-induced, site-specific recombination and next-generation sequencing. Recombination located Tel1 to a 15 kb region in 92A. Comparison of the DNA sequence in this region with the Drosophila Genetic Reference Panel of wild-type genomic sequences delimited Tel1 to a 3 bp deletion inside intron 8 of Ino80. Furthermore, CRISPR/Cas9-induced deletions surrounding the same region exhibited the Tel1 telomere phenotype, confirming a strict requirement of this intron 8 gene sequence for a proper regulation of Drosophila telomere length.
- Klíčová slova
- Drosophila melanogaster, next-generation sequencing, telomere, transposon-induced recombination,
- MeSH
- Drosophila melanogaster * genetika MeSH
- Drosophila * genetika MeSH
- genové produkty gag genetika MeSH
- mutace genetika MeSH
- telomery genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- genové produkty gag MeSH
The attrition of telomeres, the ends of eukaryote chromosomes, and activity of telomerase, the enzyme that restores telomere length, play a role in the ageing process and act as indicators of biological age. A notable feature of advanced eusocial insects is the longevity of reproductive individuals (queens and kings) compared to those from non-reproductive castes (workers and soldiers) within a given species, with a proposed link towards upregulation of telomerase activity in the somatic tissues of reproductive individuals. Given this, eusocial insects provide excellent model systems for research into ageing. We tested telomerase activity and measured telomere length in Bombus terrestris, which is a primitively eusocial insect species with several distinct features compared to advanced social insects. In somatic tissues, telomerase activity was upregulated only in the fat bodies of pre-diapause queens, and this upregulation was linked to heightened DNA synthesis. Telomere length was shorter in old queens compared to that in younger queens or workers. We speculate that (1) the upregulation of telomerase activity, together with DNA synthesis, is the essential step for intensifying metabolic activity in the fat body to build up a sufficient energy reserve prior to diapause, and that (2) the lifespan differences between B. terrestris workers and queens are related to the long diapause period of the queen. A possible relationship between telomere length regulation and TOR, FOXO, and InR as cell signaling components, was tested.
- Klíčová slova
- Ageing, Bombus, Social insect, Telomerase, Telomeres,
- MeSH
- DNA biosyntéza MeSH
- telomerasa metabolismus MeSH
- tukové těleso enzymologie MeSH
- včely enzymologie MeSH
- zkracování telomer MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA MeSH
- telomerasa MeSH
Telomerase is an enzyme that adds repeats of DNA sequences to the ends of chromosomes, thereby preventing their shortening. Telomerase activity is associated with proliferative status of cells, organismal development, and aging. We report an analysis of telomerase activity and telomere length in the honeybee, Apis mellifera. Telomerase activity was found to be regulated in a development and caste-specific manner. During the development of somatic tissues of larval drones and workers, telomerase activity declined to 10 % of its level in embryos and remained low during pupal and adult stages but was upregulated in testes of late pupae, where it reached 70 % of the embryo level. Upregulation of telomerase activity was observed in the ovaries of late pupal queens, reaching 160 % of the level in embryos. Compared to workers and drones, queens displayed higher levels of telomerase activity. In the third larval instar of queens, telomerase activity reached the embryo level, and an enormous increase was observed in adult brains of queens, showing a 70-fold increase compared to a brain of an adult worker. Southern hybridization of terminal TTAGG fragments revealed a high variability of telomeric length between different individuals, although the same pattern of hybridization signals was observed in different tissues of each individual.
- Klíčová slova
- Apis mellifera, Insects, Longevity, Telomerase, Telomere,
- MeSH
- chromozomy hmyzu genetika metabolismus MeSH
- hmyzí proteiny genetika metabolismus MeSH
- homeostáza telomer fyziologie MeSH
- telomerasa genetika metabolismus MeSH
- telomery genetika metabolismus MeSH
- včely genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hmyzí proteiny MeSH
- telomerasa MeSH
Despite a high toxicity, paraquat is one of the most widely used herbicides in the world. Our study evaluated the effect of paraquat exposure on antioxidant response and locomotion activity in Drosophila melanogaster. We examined the enzymatic activity of superoxide dismutase (SOD) and catalase, and the transcript levels of both enzymes. Flies were exposed to a wide range of paraquat concentrations (0.25 μM to 25 mM) for 12 h. SOD, at both transcript and enzymatic levels, revealed a biphasic dose-response curve with the peak at 2.5 μM paraquat. A similar dose-response curve was observed at transcript levels of catalase. Males revealed higher susceptibility to paraquat exposure, displaying higher lethality, increased levels of SOD activity, and increased peroxide levels than in females. We found that the exposure of females to 2.5 μM paraquat leads to an increase in locomotion activity. Because susceptibility to paraquat was enhanced by mating, the study supports the hypothesis of elevation of stress sensitivity as a physiological cost of reproduction.
- Klíčová slova
- Drosophila, catalase, mating, oxidative stress, paraquat, superoxide dismutase,
- MeSH
- antioxidancia metabolismus MeSH
- chování zvířat účinky léků MeSH
- Drosophila melanogaster účinky léků metabolismus MeSH
- herbicidy toxicita MeSH
- katalasa metabolismus MeSH
- oxidace-redukce MeSH
- paraquat toxicita MeSH
- peroxidy metabolismus MeSH
- rozmnožování účinky léků MeSH
- sexuální faktory MeSH
- superoxiddismutasa metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- herbicidy MeSH
- katalasa MeSH
- paraquat MeSH
- peroxidy MeSH
- superoxiddismutasa MeSH
In most eukaryotes, telomeres consist of tandem arrays of a short repetitive DNA sequence. Insect telomeres are generally constituted by a (TTAGG)n repeat motif. Usually, telomeres are maintained by telomerase, a specialized reverse transcriptase that adds this sequence to chromosome ends. We examined telomerase activity in 15 species across Insecta. Telomerase activity was revealed in Isoptera, Blattaria, Lepidoptera, Hymenoptera, Trichoptera, Coleoptera, and Sternorrhyncha. In contrast, we were not able to detect telomerase activity in Orthoptera, Zygentoma, and Phasmida. Because we found telomerase activity in phylogenetically distant species, we conclude that a distribution pattern of (TTAGG)n sequence in Insecta is generally consistent with that of telomerase activity. Thus, the TTAGG-telomerase system is functional across the Insecta. Using real-time quantitative telomeric repeat amplification protocol (RTQ-TRAP) system, we quantified telomerase activity in different developmental stages and different tissues of a cockroach, Periplaneta americana. We show that telomerase is upregulated in young instars and gradually declines during development. In adults, it is most active in testes and ovaries. Thus, the telomerase activity of hemimetabolous insects seems to be associated with cell proliferation and organismal development.
- MeSH
- bourec genetika MeSH
- fylogeneze * MeSH
- hmyz genetika MeSH
- hybridizace in situ fluorescenční MeSH
- replikace DNA genetika MeSH
- tandemové repetitivní sekvence genetika MeSH
- telomerasa genetika MeSH
- telomery genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- telomerasa MeSH
