Aging: a young mind in old bees

A new surprising study suggests that various cognitive abilities and motosensory functions remain perfectly intact as honeybee workers age. How do these findings fit in with a buzzing life

Social insects as a model to study the molecular basis of ageing

One major gap in the current knowledge of the molecular bases of ageing is that most of the work has been done using short-lived model organisms such as fruitflies, nematodes, yeast and mice. Here, we argue that ants and social bee species provide an excellent complementary system to study ageing, and this for two reasons: first, in contrast to model organisms, ant and bee queens are extraordinarily long-lived, and second, there is a tremendous variation in lifespan among the genetically identical queens, workers (non-reproductive females) and males, with queens living up to 500 times longer than males and 10 times longer than workers. We review recent experimental work aimed at testing the role of antioxidant genes within the conceptual framework of the free radical theory of ageing, as well as studies investigating the role of juvenile hormone, vitellogenin and telomeres as mediators of ageing in social insects

Queen control over reproductive decisions--no sexual deception in the ant Lasius niger

Queen-worker conflicts in social insect societies have received much attention in the past decade. In many species workers modify the colony sex ratio to their own advantage or produce their own male offspring. In some other species, however, queens seem to be able to prevent workers from making selfish reproductive decisions. So far, little effort has been made to find out how queens may keep control over sex ratio and male parentage. In this study we use a Lasius niger population under apparent queen control to show that sexual deception cannot explain queen dominance in this population. The sexual deception hypothesis postulates that queens should prevent workers from discriminating against males by disguising male brood as females. Contrary to the predictions of this hypothesis, we found that workers are able to distinguish male and female larvae early in their development: in early spring workers generally placed only either female or male larvae in the uppermost chambers of the nest, although both types of larvae must have been present. At this time males were only at 11% of their final dry weight, a developmental stage at which (according to two models) workers would still have benefited from replacing queen-produced males by females or worker-produced males. This study thus demonstrates that sexual deception cannot account for the apparent queen control over colony sex ratio and male parentage in L. niger

How to fool a virgin: Artificial dealation triggers oviposition in virgin Lasius niger queens

Once inseminated, ant queens rapidly shed their wings and start to lay eggs. Here we test whether there is a causal link between dealation and oviposition in the ant Lasius niger. We show that artificially dealated virgin queens start to lay eggs shortly after wing removal, whereas winged virgin queens hardly ever lay eggs. Dealate virgins do, however, produce fewer eggs than mated queens. These findings indicate that dealation does induce egg-laying, and that other factors, such as mating and/or insemination, further stimulate oviposition under natural conditions

How to fool a virgin: Artificial dealation triggers oviposition in virgin Lasius niger queens

Abstract.: Once inseminated, ant queens rapidly shed their wings and start to lay eggs. Here we test whether there is a causal link between dealation and oviposition in the ant Lasius niger. We show that artificially dealated virgin queens start to lay eggs shortly after wing removal, whereas winged virgin queens hardly ever lay eggs. Dealate virgins do, however, produce fewer eggs than mated queens. These findings indicate that dealation does induce egg-laying, and that other factors, such as mating and/or insemination, further stimulate oviposition under natural condition

Long live the queen: studying aging in social insects

Aging is a fascinating, albeit controversial, chapter in biology. Few other subjects have elicited more than a century of ever-increasing scientific interest. In this review, we discuss studies on aging in social insects, a group of species that includes ants and termites, as well as certain bee and wasp species. One striking feature of social insects is the lifespan of queens (reproductive females), which can reach nearly 30 years in some ant species. This is over 100 times the average lifespan of solitary insects. Moreover, there is a tremendous variation in lifespan among castes, with queens living up to 500 times longer than males and 10 times longer than workers (non-reproductive individuals). This lifespan polymorphism has allowed researchers to test the evolutionary theory of aging and - more recently - to investigate the proximate causes of aging. The originality of these studies lies in their use of naturally evolved systems to address questions related to aging and lifespan determination that cannot be answered using the conventional model organism

Antoni Mironowicz, Kościół prawosławny w Polsce, Białystok 2006, s. 917.

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An annotated cDNA library and microarray for large-scale gene-expression studies in the ant Solenopsis invicta

Ants display a range of fascinating behaviors, a remarkable level of intra-species phenotypic plasticity and many other interesting characteristics. Here we present a new tool to study the molecular mechanisms underlying these traits: a tentatively annotated expressed sequence tag (EST) resource for the fire ant Solenopsis invicta. From a normalized cDNA library we obtained 21,715 ESTs, which represent 11,864 putatively different transcripts with very diverse molecular functions. All ESTs were used to construct a cDNA microarray

Computer tomography guided transthoracic periaortic abscess needle biopsy in late mediastinitis after heart surgery

Mediastinitis is a well-known complication of open heart surgery. Abscess as late complication, presenting years after heart surgery, is adegnotical. Transthoracic needle biopsies of lung parenchyma guided by computer tomography are widely accepted. The puncture of periaortic masses is not routinely performed. We report the case of an encapsulated mediastinal abscess localized next to ascending vascular graft. The febrile 47-year-old white male patient with history of Bentall operation was admitted to Cardiac Surgery Department. He was transferred for urgent chest tomography after International Normalization Ratio was reversed by prothrombin complex concentrate. Tomography revealed 7 × 5 × 4 cm mass between the sternum and ascending aorta, that was punctured by the needle. After biopsy specimen was sent for microbiology, the patient was transferred for surgery. There was no vascular graft invasion by the mass. The surgery was limited to abscess removal with postoperative drainage of periaortic area. The 6-week antibiotic therapy was applied. Patient recovered uneventfully