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Harrison MC, Niño LMJ, Rodrigues MA, Ryll J, Flatt T, Oettler J, Bornberg-Bauer E. Gene Coexpression Network Reveals Highly Conserved, Well-Regulated Anti-Ageing Mechanisms in Old Ant Queens. Genome Biol Evol 2021; 13:6263858. [PMID: 33944936 PMCID: PMC8214412 DOI: 10.1093/gbe/evab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2021] [Indexed: 12/11/2022] Open
Abstract
Evolutionary theories of ageing predict a reduction in selection efficiency with age, a so-called “selection shadow,” due to extrinsic mortality decreasing effective population size with age. Classic symptoms of ageing include a deterioration in transcriptional regulation and protein homeostasis. Understanding how ant queens defy the trade-off between fecundity and lifespan remains a major challenge for the evolutionary theory of ageing. It has often been discussed that the low extrinsic mortality of ant queens, that are generally well protected within the nest by workers and soldiers, should reduce the selection shadow acting on old queens. We tested this by comparing strength of selection acting on genes upregulated in young and old queens of the ant, Cardiocondyla obscurior. In support of a reduced selection shadow, we find old-biased genes to be under strong purifying selection. We also analyzed a gene coexpression network (GCN) with the aim to detect signs of ageing in the form of deteriorating regulation and proteostasis. We find no evidence for ageing. In fact, we detect higher connectivity in old queens indicating increased transcriptional regulation with age. Within the GCN, we discover five highly correlated modules that are upregulated with age. These old-biased modules regulate several antiageing mechanisms such as maintenance of proteostasis, transcriptional regulation, and stress response. We observe stronger purifying selection on central hub genes of these old-biased modules compared with young-biased modules. These results indicate a lack of transcriptional ageing in old C. obscurior queens, possibly facilitated by strong selection at old age and well-regulated antiageing mechanisms.
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Affiliation(s)
- Mark C Harrison
- Institute for Evolution and Biodiversity, University of Münster, Germany
| | | | | | - Judith Ryll
- Institute for Evolution and Biodiversity, University of Münster, Germany
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Switzerland
| | - Jan Oettler
- Institut für Zoologie/Evolutionsbiologie, University of Regensburg, Germany
| | - Erich Bornberg-Bauer
- Department of Biology, University of Fribourg, Switzerland.,Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
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2
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Koubová J, Jehlík T, Kodrík D, Sábová M, Šima P, Sehadová H, Závodská R, Frydrychová RČ. Telomerase activity is upregulated in the fat bodies of pre-diapause bumblebee queens (Bombus terrestris). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 115:103241. [PMID: 31536769 DOI: 10.1016/j.ibmb.2019.103241] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
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.
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Affiliation(s)
- Justina Koubová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Tomáš Jehlík
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Dalibor Kodrík
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Michala Sábová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Peter Šima
- Koppert s.r.o., Komárňanská cesta 13, 940 01, Nové Zámky, Slovakia
| | - Hana Sehadová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Radka Závodská
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Pedagogy, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Radmila Čapková Frydrychová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic.
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3
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Kohlmeier P, Alleman AR, Libbrecht R, Foitzik S, Feldmeyer B. Gene expression is more strongly associated with behavioural specialization than with age or fertility in ant workers. Mol Ecol 2019; 28:658-670. [PMID: 30525254 DOI: 10.1111/mec.14971] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 11/09/2018] [Accepted: 11/15/2018] [Indexed: 12/19/2022]
Abstract
The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialization from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3,644 genes were associated with behavioural specialization which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characterized by an upregulation of three Vitellogenin (Vg) genes, one of which, Vg-like A, was the most differentially expressed gene that was recently shown experimentally to control the switch from brood to worker care. The expression of Conventional Vg was unlinked to behavioural specialization, age or fertility, which contrasts to studies on bees and some ants. Diversity in Vg/Vg-like copy number and expression bias across ants supports subfunctionalization of Vg genes and indicates that some regulatory mechanisms of division of labour diverged in different ant lineages. Simulations revealed that our experimental dissociation of co-varying factors reduced transcriptomic noise, suggesting that confounding factors could potentially explain inconsistencies across transcriptomic studies of behavioural specialization in ants. Thus, our study reveals that worker gene expression is mainly linked to the worker's function for the colony and provides novel insights into the evolution of sociality in ants.
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Affiliation(s)
- Philip Kohlmeier
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Austin R Alleman
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Romain Libbrecht
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
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Lucas ER, Keller L. Elevated expression of ageing and immunity genes in queens of the black garden ant. Exp Gerontol 2018; 108:92-98. [PMID: 29625209 DOI: 10.1016/j.exger.2018.03.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
Studies in model organisms have identified a variety of genes whose expression can be experimentally modulated to produce changes in longevity, but whether these genes are the same as those involved in natural variation in lifespan remains unclear. Social insects boast some of the largest lifespan differences known between plastic phenotypes, with queen and worker lifespans differing by an order of magnitude despite no systematic nucleotide sequence differences between them. The contrasting lifespans of queens and workers are thus the result of differences in gene expression. We used RNA sequencing of brains and legs in 1-day-old and 2-month-old individuals of the ant Lasius niger to determine whether genes with queen-biased expression are enriched for genes linked to ageing in model organisms. Because the great longevity of queens may require investment into immune processes, we also investigated whether queen-biased genes are enriched for genes with known roles in immunity. Queen-biased genes in legs were enriched for ageing genes and for genes associated with increasing rather than decreasing lifespan. Queen-biased genes in legs were also enriched for immune genes, but only in 1-day-old individuals, perhaps linked to the changing roles of workers with age. Intriguingly, the single most differentially expressed gene between 1-day-old queen and worker brains was an extra-cellular form of CuZn Superoxide Dismutase (SOD3), raising the possibility of an important role of anti-oxidant genes in modulating lifespan.
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Affiliation(s)
- Eric R Lucas
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Laurent Keller
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
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5
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Testing the effect of paraquat exposure on genomic recombination rates in queens of the western honey bee, Apis mellifera. Genetica 2018; 146:171-178. [PMID: 29397499 DOI: 10.1007/s10709-018-0009-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 01/30/2018] [Indexed: 10/18/2022]
Abstract
The rate of genomic recombination displays evolutionary plasticity and can even vary in response to environmental factors. The western honey bee (Apis mellifera L.) has an extremely high genomic recombination rate but the mechanistic basis for this genome-wide upregulation is not understood. Based on the hypothesis that meiotic recombination and DNA damage repair share common mechanisms in honey bees as in other organisms, we predicted that oxidative stress leads to an increase in recombination rate in honey bees. To test this prediction, we subjected honey bee queens to oxidative stress by paraquat injection and measured the rates of genomic recombination in select genome intervals of offspring produced before and after injection. The evaluation of 26 genome intervals in a total of over 1750 offspring of 11 queens by microsatellite genotyping revealed several significant effects but no overall evidence for a mechanistic link between oxidative stress and increased recombination was found. The results weaken the notion that DNA repair enzymes have a regulatory function in the high rate of meiotic recombination of honey bees, but they do not provide evidence against functional overlap between meiotic recombination and DNA damage repair in honey bees and more mechanistic studies are needed.
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Lucas ER, Augustyniak M, Kędziorski A, Keller L. Lifespan differences between queens and workers are not explained by rates of molecular damage. Exp Gerontol 2017; 92:1-6. [PMID: 28285146 DOI: 10.1016/j.exger.2017.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/15/2017] [Accepted: 03/07/2017] [Indexed: 12/22/2022]
Abstract
The biological processes that underlie senescence are of universal biological importance, yet they remain poorly understood. A popular theory proposes that senescence is the result of limited investment into mechanisms involved in the prevention and repair of molecular damage, leading to an accumulation of molecular damage with age. In ants, queen and worker lifespans differ by an order of magnitude, and this remarkable difference in lifespan has been shown to be associated with differences in the expression of genes involved in DNA and protein repair. Here we use the comet assay and Western Blotting for poly-ubiquitinated proteins to explore whether these differences in expression lead to differences in the accumulation of DNA damage (comet assay) or protein damage (protein ubiquitination) with age. Surprisingly, there was no difference between queens and workers in the rate of accumulation of DNA damage. We also found that levels of ubiquitinated proteins decreased with age, as previously reported in honeybees. This is in contrast to what has been found in model organisms such as worms and flies. Overall, these results reveal that the link between investment into macromolecular repair, age-related damage accumulation and lifespan is more complex than usually recognised.
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Affiliation(s)
- Eric R Lucas
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Maria Augustyniak
- University of Silesia in Katowice, Faculty of Biology & Environmental Protection, Department of Animal Physiology & Ecotoxicology, Bankowa 9, PL 40-007 Katowice, Poland
| | - Andrzej Kędziorski
- University of Silesia in Katowice, Faculty of Biology & Environmental Protection, Department of Animal Physiology & Ecotoxicology, Bankowa 9, PL 40-007 Katowice, Poland
| | - Laurent Keller
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
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7
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Lucas ER, Privman E, Keller L. Higher expression of somatic repair genes in long-lived ant queens than workers. Aging (Albany NY) 2016; 8:1940-1951. [PMID: 27617474 PMCID: PMC5076446 DOI: 10.18632/aging.101027] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/19/2016] [Indexed: 12/20/2022]
Abstract
Understanding why organisms senesce is a fundamental question in biology. One common explanation is that senescence results from an increase in macromolecular damage with age. The tremendous variation in lifespan between genetically identical queen and worker ants, ranging over an order of magnitude, provides a unique system to study how investment into processes of somatic maintenance and macromolecular repair influence lifespan. Here we use RNAseq to compare patterns of expression of genes involved in DNA and protein repair of age-matched queens and workers. There was no difference between queens and workers in 1-day-old individuals, but the level of expression of these genes increased with age and this up-regulation was greater in queens than in workers, resulting in significantly queen-biased expression in 2-month-old individuals in both legs and brains. Overall, these differences are consistent with the hypothesis that higher longevity is associated with increased investment into somatic repair.
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Affiliation(s)
- Eric R. Lucas
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Eyal Privman
- Department of Evolutionary and Environmental Biology and Institute of Evolution, University of Haifa, 31905 Haifa, Israel
| | - Laurent Keller
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland
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de Verges J, Nehring V. A critical look at proximate causes of social insect senescence: damage accumulation or hyperfunction? CURRENT OPINION IN INSECT SCIENCE 2016; 16:69-75. [PMID: 27720053 DOI: 10.1016/j.cois.2016.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/26/2016] [Accepted: 05/02/2016] [Indexed: 06/06/2023]
Abstract
Social insects have received attention for their extreme lifespan variation and reversal of the fecundity/longevity trade-off. However, proximate causes of senescence in general are disputed, and social insects often fail to meet the predictions of prevailing models. We present evidence for and against the long-held free radical theory of aging in social insects, and consider the application of the competing hyperfunction theory. Current results present problems for both theories, and a more complex picture of the biological processes involved emerges. The eusocial life style might allow colonies to allocate damage in ways that create seemingly senescence-free life histories. Only experimental approaches characterizing multiple senescence factors simultaneously will shed light on how social insects defy the conventions of senescence.
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Affiliation(s)
- Jane de Verges
- University of Freiburg, Biology I, Evolution & Ecology, Hauptstraße 1, D-79104 Freiburg, Germany
| | - Volker Nehring
- University of Freiburg, Biology I, Evolution & Ecology, Hauptstraße 1, D-79104 Freiburg, Germany.
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9
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Lucas ER, Keller L. Ageing and somatic maintenance in social insects. CURRENT OPINION IN INSECT SCIENCE 2014; 5:31-36. [PMID: 32846739 DOI: 10.1016/j.cois.2014.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 09/15/2014] [Accepted: 09/17/2014] [Indexed: 06/11/2023]
Abstract
Social insects offer exciting prospects for ageing research due to the striking differences in lifespan among castes, with queens living up to an order of magnitude longer than workers. A popular theory is that senescence is primarily the result of an accumulation of somatic damage with age, balanced by investment into processes of somatic maintenance. Investigation of these predictions in social insects has produced mixed results: neither damage accumulation nor investment into somatic maintenance is consistently different between castes with different lifespans. We discuss some limitations of the studies conducted thus far and consider an alternative proximate theory of ageing that has been recently proposed.
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Affiliation(s)
- Eric R Lucas
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Laurent Keller
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
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Cram DL, Blount JD, Young AJ. Oxidative status and social dominance in a wild cooperative breeder. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12317] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dominic L. Cram
- Centre for Ecology & Conservation College of Life & Environmental Sciences University of Exeter Penryn Campus Cornwall TR10 9FE UK
- Department of Zoology University of Cambridge Cambridge CB2 3EJ UK
| | - Jonathan D. Blount
- Centre for Ecology & Conservation College of Life & Environmental Sciences University of Exeter Penryn Campus Cornwall TR10 9FE UK
| | - Andrew J. Young
- Centre for Ecology & Conservation College of Life & Environmental Sciences University of Exeter Penryn Campus Cornwall TR10 9FE UK
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11
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Dixon L, Kuster R, Rueppell O. Reproduction, social behavior, and aging trajectories in honeybee workers. AGE (DORDRECHT, NETHERLANDS) 2014; 36:89-101. [PMID: 23765046 PMCID: PMC3889882 DOI: 10.1007/s11357-013-9546-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 05/20/2013] [Indexed: 05/26/2023]
Abstract
While a negative correlation between reproduction and life span is commonly observed, specialized reproductive individuals outlive their non-reproductive nestmates in all eusocial species, including the honeybee, Apis mellifera (L). The consequences of reproduction for individual life expectancy can be studied directly by comparing reproductive and non-reproductive workers. We quantified the life span consequences of reproduction in honeybee workers by removal of the queen to trigger worker reproduction. Furthermore, we observed the social behavior of large cohorts of workers under experimental and control conditions to test for associations with individual life expectancy. Worker life expectancy was moderately increased by queen removal. Queenless colonies contained a few long-lived workers, and oviposition behavior was associated with a strong reduction in mortality risk, indicating that a reproductive role confers a significant survival advantage. This finding is further substantiated by an association between brood care behavior and worker longevity that depends on the social environment. In contrast, other in-hive activities, such as fanning, trophallaxis, and allogrooming did not consistently affect worker life expectancy. The influence of foraging varied among replicates. An earlier age of transitioning from in-hive tasks to outside foraging was always associated with shorter life spans, in accordance with previous studies. In sum, our studies quantify how individual mortality is affected by particular social roles and colony environments and demonstrate interactions between the two. The exceptional, positive association between reproduction and longevity in honeybees extends to within-caste plasticity, which may be exploited for mechanistic studies.
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Affiliation(s)
- Luke Dixon
- />Department of Biology, University of North Carolina at Greensboro, 1000 Spring Garden Street, 312 Eberhart Building, Greensboro, NC 27403 USA
- />Life Science Department, Winston-Salem State University, 601 S. Martin Luther King, Jr. Drive, Winston-Salem, NC 27110 USA
| | - Ryan Kuster
- />Department of Biology, University of North Carolina at Greensboro, 1000 Spring Garden Street, 312 Eberhart Building, Greensboro, NC 27403 USA
- />Bioinformatics Graduate Program, North Carolina State University, Raleigh, NC 27695 USA
| | - Olav Rueppell
- />Department of Biology, University of North Carolina at Greensboro, 1000 Spring Garden Street, 312 Eberhart Building, Greensboro, NC 27403 USA
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Tatarinova T, Elhaik E, Pellegrini M. Cross-species analysis of genic GC3 content and DNA methylation patterns. Genome Biol Evol 2013; 5:1443-56. [PMID: 23833164 PMCID: PMC3762193 DOI: 10.1093/gbe/evt103] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The GC content in the third codon position (GC3) exhibits a unimodal distribution in many plant and animal genomes. Interestingly, grasses and homeotherm vertebrates exhibit a unique bimodal distribution. High GC3 was previously found to be associated with variable expression, higher frequency of upstream TATA boxes, and an increase of GC3 from 5′ to 3′. Moreover, GC3-rich genes are predominant in certain gene classes and are enriched in CpG dinucleotides that are potential targets for methylation. Based on the GC3 bimodal distribution we hypothesize that GC3 has a regulatory role involving methylation and gene expression. To test that hypothesis, we selected diverse taxa (rice, thale cress, bee, and human) that varied in the modality of their GC3 distribution and tested the association between GC3, DNA methylation, and gene expression. We examine the relationship between cytosine methylation levels and GC3, gene expression, genome signature, gene length, and other gene compositional features. We find a strong negative correlation (Pearson’s correlation coefficient r = −0.67, P value < 0.0001) between GC3 and genic CpG methylation. The comparison between 5′-3′ gradients of CG3-skew and genic methylation for the taxa in the study suggests interplay between gene-body methylation and transcription-coupled cytosine deamination effect. Compositional features are correlated with methylation levels of genes in rice, thale cress, human, bee, and fruit fly (which acts as an unmethylated control). These patterns allow us to generate evolutionary hypotheses about the relationships between GC3 and methylation and how these affect expression patterns. Specifically, we propose that the opposite effects of methylation and compositional gradients along coding regions of GC3-poor and GC3-rich genes are the products of several competing processes.
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Affiliation(s)
- Tatiana Tatarinova
- Laboratory of Applied Pharmacokinetics and Bioinformatics, University of Southern California.
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Somatic maintenance resources in the honeybee worker fat body are distributed to withstand the most life-threatening challenges at each life stage. PLoS One 2013; 8:e69870. [PMID: 23940531 PMCID: PMC3734224 DOI: 10.1371/journal.pone.0069870] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 06/12/2013] [Indexed: 01/04/2023] Open
Abstract
In a global transcriptome analysis of three natural and three manipulated honeybee worker phenotypes at different ages, we have investigated the distribution of investment in somatic maintenance of the fat body. Gene expression is modulated so that the bees are able to resist the most life-threatening challenges at the actual life stage. Different modes of maintenance and repair are regulated, apparently to meet the environmental challenges most detrimental to survival and reproductive potential for the hive. We observed a broad down-regulation of genomic and cellular maintenance in the short-lived foragers and nurse bees compared to the long-lived winter bees. Our results show that survival and reproduction of the entire hive is given priority over the individual bees, hence supporting the idea of the honeybee society as a superorganism. Our results also fit the disposable soma theory of aging.
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Metcalfe NB, Alonso-Alvarez C. Oxidative stress as a life-history constraint: the role of reactive oxygen species in shaping phenotypes from conception to death. Funct Ecol 2010. [DOI: 10.1111/j.1365-2435.2010.01750.x] [Citation(s) in RCA: 394] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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