scholarly journals Queen loss increases worker survival in leaf-cutting ants under paraquat-induced oxidative stress

2021 ◽  
Vol 376 (1823) ◽  
pp. 20190735 ◽  
Author(s):  
Megha Majoe ◽  
Romain Libbrecht ◽  
Susanne Foitzik ◽  
Volker Nehring
Keyword(s):  
Oxidative Stress ◽  
Social Insects ◽  
Worker Reproduction ◽  
Theme Issue ◽  
Leaf Cutting ◽  
Stress Oxidative ◽  
Myrmicine Ants ◽  
Atta Colombica ◽  
Acromyrmex Echinatior ◽  
Solitary Species

Longevity is traded off with fecundity in most solitary species, but the two traits are positively linked in social insects. In ants, the most fecund individuals (queens and kings) live longer than the non-reproductive individuals, the workers. In many species, workers may become fertile following queen loss, and recent evidence suggests that worker fecundity extends worker lifespan. We postulated that this effect is in part owing to improved resilience to oxidative stress, and tested this hypothesis in three Myrmicine ants: Temnothorax rugatulus, and the leaf-cutting ants Atta colombica and Acromyrmex echinatior . We removed the queen from colonies to induce worker reproduction and subjected workers to oxidative stress. Oxidative stress drastically reduced survival, but this effect was less pronounced in leaf-cutting ant workers from queenless nests. We also found that, irrespective of oxidative stress, outside workers died earlier than inside workers did, likely because they were older. Since At. colombica workers cannot produce fertile offspring, our results indicate that direct reproduction is not necessary to extend the lives of queenless workers. Our findings suggest that workers are less resilient to oxidative stress in the presence of the queen, and raise questions on the proximate and ultimate mechanisms underlying socially mediated variation in worker lifespan. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’

scholarly journals Optimality in a partitioned task performed by social insects

2008 ◽  
Vol 4 (6) ◽  
pp. 627-629 ◽  
Author(s):  
Martin Burd ◽  
Jerome J Howard
Keyword(s):  
Social Insects ◽  
Social Insect ◽  
Leaf Tissue ◽  
Leaf Fragment ◽  
Ant Colonies ◽  
Tissue Processing ◽  
Leaf Cutting ◽  
Laboratory Colonies ◽  
Atta Colombica ◽  
Behavioural Adaptations

Biologists have long been aware that adaptations should not be analysed in isolation from the function of the whole organism. Here, we address the equivalent issue at the scale of a social insect colony: the optimality of component behaviours in a partitioned sequence of tasks. In colonies of Atta colombica , a leaf-cutting ant, harvested leaf tissue is passed from foragers to nest workers that distribute, clean, shred and implant the tissue in fungal gardens. In four laboratory colonies of A. colombica , we found that the highest colony-wide rate of leaf tissue processing in the nest was achieved when leaf fragment sizes were suboptimal for individual delivery rate by foragers. Leaf-cutting ant colonies appear to compromise the efficiency of collecting leaf tissue in order to increase their ability to handle the material when it arrives in the nest. Such compromise reinforces the idea that behavioural adaptations, like adaptations in general, must be considered within the context of the larger entity of which they are a part.

scholarly journals Adaptive social immunity in leaf-cutting ants

2009 ◽  
Vol 5 (4) ◽  
pp. 446-448 ◽  
Author(s):  
Tom N. Walker ◽  
William O. H. Hughes
Keyword(s):  
Immune Response ◽  
Social Insects ◽  
Social Immunity ◽  
Group Level ◽  
Effective Response ◽  
Fungal Parasite ◽  
The Social ◽  
Leaf Cutting ◽  
The Individual ◽  
Acromyrmex Echinatior

Social insects have evolved a suite of sophisticated defences against parasites. In addition to the individual physiological immune response, social insects also express ‘social immunity’ consisting of group-level defences and behaviours that include allogrooming. Here we investigate whether the social immune response of the leaf-cutting ant Acromyrmex echinatior reacts adaptively to the virulent fungal parasite, Metarhizium anisopliae . We ‘immunized’ mini-nests of the ants by exposing them twice to the parasite and then compared their social immune response with that of naive mini-nests that had not been experimentally exposed to the parasite. Ants allogroomed individuals exposed to the parasite, doing this both for those freshly treated with the parasite, which were infectious but not yet infected, and for those treated 2 days previously, which were already infected but no longer infectious. We found that ants exposed to the parasite received more allogrooming in immunized mini-nests than in naive mini-nests. This increased the survival of the freshly treated ants, but not those that were already infected. The results thus indicate that the social immune response of this leaf-cutting ant is adaptive, with the group exhibiting a greater and more effective response to a parasite that it has previously been exposed to.

scholarly journals Oxidative stress and senescence in social insects: a significant but inconsistent link?

2021 ◽  
Vol 376 (1823) ◽  
pp. 20190732 ◽  
Author(s):  
Boris H. Kramer ◽  
Volker Nehring ◽  
Anja Buttstedt ◽  
Jürgen Heinze ◽  
Judith Korb ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Social Insects ◽  
Social Life ◽  
Life Histories ◽  
Antioxidant Defenses ◽  
Theme Issue ◽  
Social Species ◽  
Oxidative Damage To Proteins ◽  
The Relationship

The life-prolonging effects of antioxidants have long entered popular culture, but the scientific community still debates whether free radicals and the resulting oxidative stress negatively affect longevity. Social insects are intriguing models for analysing the relationship between oxidative stress and senescence because life histories differ vastly between long-lived reproductives and the genetically similar but short-lived workers. Here, we present the results of an experiment on the accumulation of oxidative damage to proteins, and a comparative analysis of the expression of 20 selected genes commonly involved in managing oxidative damage, across four species of social insects: a termite, two bees and an ant. Although the source of analysed tissue varied across the four species, our results suggest that oxidative stress is a significant factor in senescence and that its manifestation and antioxidant defenses differ among species, making it difficult to find general patterns. More detailed and controlled investigations on why responses to oxidative stress may differ across social species may lead to a better understanding of the relations between oxidative stress, antioxidants, social life history and senescence. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?'

scholarly journals The effect of environmental stress on ageing in a termite species with low social complexity

2021 ◽  
Vol 376 (1823) ◽  
pp. 20190739 ◽  
Author(s):  
Veronika Rau ◽  
Judith Korb
Keyword(s):  
Oxidative Stress ◽  
Environmental Stress ◽  
Social Insects ◽  
Social Complexity ◽  
Experimental Studies ◽  
Theme Issue ◽  
Termite Species ◽  
Trade Off ◽  
Temperature Regimes ◽  
Transcriptome Signature

Social insects seem to have overcome the almost universal trade-off between fecundity and longevity as queens can be highly fecund and at the same time reach lifespans of decades. By contrast, their non-reproducing workers are often short-lived. One hypothesis to explain the long lifespan of queens is that they are better protected against stress than their workers. However, evidence is controversial and experimental studies are scarce. We aimed at manipulating environmental stress and ageing by exposing colonies of the less-socially complex termite Cryptotermes secundus to temperature regimes that differed in variance. In contrast with expectation, constant temperatures imposed more stress than variable temperatures. Survival of queens and workers as well as queens' fecundity were partly reduced under constant conditions and both castes showed signs of ageing in the transcriptome signature under constant conditions. There was a clear oxidative stress defence signal under constant conditions that was, surprisingly, stronger for workers than queens. We discuss how our results relate to social complexity. We argue that workers that are totipotent to become reproductives, like in C. secundus , should invest more in ‘anti-ageing' mechanisms than sterile workers because the former can still reproduce and have not reached maturity yet. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’

scholarly journals Architecture, space and information in constructions built by humans and social insects: a conceptual review

2018 ◽  
Vol 373 (1753) ◽  
pp. 20170244 ◽  
Author(s):  
Tim Ireland ◽  
Simon Garnier
Keyword(s):  
Social Insects ◽  
Review Paper ◽  
Theoretical Framework ◽  
Collective Behaviour ◽  
Informational Content ◽  
Spatial Constraints ◽  
Theme Issue ◽  
Interdisciplinary Approaches ◽  
Interdisciplinary Exchange ◽  
Cross Fertilization

The similarities between the structures built by social insects and by humans have led to a convergence of interests between biologists and architects. This new, de facto interdisciplinary community of scholars needs a common terminology and theoretical framework in which to ground its work. In this conceptually oriented review paper, we review the terms ‘information’, ‘space’ and ‘architecture’ to provide definitions that span biology and architecture. A framework is proposed on which interdisciplinary exchange may be better served, with the view that this will aid better cross-fertilization between disciplines, working in the areas of collective behaviour and analysis of the structures and edifices constructed by non-humans; and to facilitate how this area of study may better contribute to the field of architecture. We then use these definitions to discuss the informational content of constructions built by organisms and the influence these have on behaviour, and vice versa. We review how spatial constraints inform and influence interaction between an organism and its environment, and examine the reciprocity of space and information on construction and the behaviour of humans and social insects. This article is part of the theme issue ‘Interdisciplinary approaches for uncovering the impacts of architecture on collective behaviour’.

Dispersal of Miconia argentea seeds by the leaf-cutting ant Atta colombica

1998 ◽  
Vol 14 (5) ◽  
pp. 705-710 ◽  
Author(s):  
J. W. Dalling ◽  
Rainer Wirth
Keyword(s):  
Seedling Recruitment ◽  
Atta Cephalotes ◽  
Brazilian Cerrado ◽  
Atta Laevigata ◽  
Cerrado Vegetation ◽  
Brosimum Alicastrum ◽  
Leaf Cutting ◽  
Single Night ◽  
Local Recruitment ◽  
Atta Colombica

While leaf-cutter ants are thought to collect mainly vegetative plant material, they have also been observed collecting seeds or fruit parts on the forest floor (Alvarez-Buylla & Martínez-Ramos 1990, Kaspari 1996). For example, leaf-cutter ants have been observed carrying considerable numbers of Brosimum alicastrum Sw. and Cecropia spp. seeds into their nests (Wirth 1996) and Leal & Oliveira (1998; pers. comm.) found them foraging on the fruits and seeds of 19 different species of Brazilian cerrado vegetation, including six Miconia species. Under some circumstances, seed removal and relocation by leaf cutter ants might even be sufficient to affect local recruitment patterns of trees. For example, in Costa Rica, Atta cephalotes can remove all fallen fig fruit from beneath a Ficus hondurensis crown in a single night (Roberts & Heithaus 1986), while in Venezuela, seedling recruitment of the savanna tree Tapirira velutinifolia was positively associated with the seed harvesting and seed cleaning activities of the ant Atta laevigata (Farji Brenner & Silva 1996).

Oxidative stress in primary culture hepatocytes isolated from partially hepatectomized rats

2007 ◽  
Vol 85 (10) ◽  
pp. 1047-1051 ◽  
Author(s):  
Daniel Francés ◽  
M. Teresa Ronco ◽  
Elena Ochoa ◽  
M. Luján Alvarez ◽  
Ariel Quiroga ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Primary Culture ◽  
Cell Injury ◽  
Cultured Cells ◽  
Male Wistar Rats ◽  
Metabolic Activities ◽  
Stress Oxidative ◽  
Species Production

The aim of this study was to evaluate the influence of partial hepatectomy prior to cell isolation on hepatocytes in vitro. We characterized the possible changes of various stress oxidative parameters within the first 24 h after seeding. Male Wistar rats served as donors. Hepatocytes were isolated by collagenase digestion from either liver of simulated surgery (SH) or from liver 1 h after 70% hepatectomy (PH), and the changes in stress parameters were analyzed after 1, 3, 18, and 24 h in culture. At 24 h, only hepatocytes from PH maintained significantly increased reactive oxygen species production, oxidized glutathione percentage, and Cu/Zn superoxide dismutase and catalase activities. Our results show that hepatocytes suffer significant cell injury as a result of the isolation procedure, but primary cultured cells from SH metabolically recover from this stress after 18 h. After this time, primary culture hepatocytes primed by PH maintain their in vivo-like metabolic activities (increase in both oxidative stress and antioxidant status).

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