Eye colour as a genetic marker for fertility and fecundity of Triatoma infestans (Klug, 1834) Hemiptera, Reduviidae, Triatominae

Eye colour of Triatoma infestans is controlled at a single autosomal locus, with black-eye as the dominant gene and red-eye as the recessive. Inheritance of these characters follows a classical Mendelian system, enabling eye colour to be used as a marker for studies of mating frequency. We found no significant differences in oviposition rates and egg hatching rates irrespective of parental phenotypes. Different mating schedules between red-eye and black-eye parents showed that eye colour did not affect mating competence. Females mated with a single male or with different males together or in succession produced similar numbers of fertile eggs, with the eye colour of the offspring reflecting exposure to the different males. We conclude that although a single mating can provide sufficient sperm for the whole reproductive life of the female, multiple matings can result in balanced assortative sperm usage from the spermatheca.

Low relatedness among cooperatively breeding workers of the greenhead ant Rhytidoponera metallica

The greenhead ant Rhytidoponera metallica has long been recognized as posing a potential challenge to kin selection theory because it has large queenless colonies where apparently many of the morphological workers are mated and reproducing. However this species has never been studied genetically and important elements of its breeding system and kin structure remain uncertain. We used microsatellite markers to measure the relatedness among nestmates unravel the fine-scale population genetic structure and infer the breeding system of R. metallica. The genetic relatedness among worker nestmates is very low but significantly greater than zero (r = 0.082 +/- 0.015) which demonstrates that nests contain many distantly related breeders. The inbreeding coefficient is very close to and not significantly different from zero indicating random mating and lack of microgeographic genetic differentiation. On average. closely located nests are not more similar genetically than distant nests which is surprising as new colonies form by budding and female dispersal is restricted. Lack of inbreeding and absence of population viscosity indicates high gene flow mediated by males. Overall the genetic pattern detected in R. metallica suggests that a high number of moderately related workers mate with unrelated males from distant nests. This breeding system results in the lowest relatedness among nestmates reported for social insect species where breeders and helpers are not morphologically differentiated. [References: 69]

Foreign ant queens are accepted but produce fewer offspring.

Understanding social evolution requires us to understand the processes regulating the number of breeders within social groups and how they partition reproduction. Queens in polygynous (multiple queens per colony) ants often seek adoption in established colonies instead of founding a new colony independently. This mode of dispersal leads to potential conflicts, as kin selection theory predicts that resident workers should favour nestmate queens over foreign queens. Here we compared the survival of foreign and resident queens as well as their relative reproductive share. We used the ant Formica exsecta to construct colonies consisting of one queen with workers related to this resident queen and introduced a foreign queen. We found that the survival of foreign queens did not differ from that of resident queens over a period of 136 days. However, the genetic analyses revealed that resident queens produced a 1.5-fold higher number of offspring than introduced queens, and had an equal or higher share in 80% of the colonies. These data indicate that some discrimination can occur against dispersing individuals and that dispersal can thus have costs in terms of direct reproduction for dispersing queens.

Ant queens (Hymenoptera: Formicidae) are attracted to fungal pathogens during the initial stage of colony founding

Ant queens that attempt to disperse and found new colonies independently face high mortality risks. The exposure of queens to soil entomopathogens during claustral colony founding may be particularly harmful, as founding queens lack the protection conferred by mature colonies. Here, we tested the hypotheses that founding queens (I) detect and avoid nest sites that are contaminated by fungal pathogens, and (II) tend to associate with other queens to benefit from social immunity when nest sites are contaminated. Surprisingly, in nest choice assays, young Formica selysi BONDROIT, 1918 queens had an initial preference for nest sites contaminated by two common soil entomopathogenic fungi, Beauveria bassiana and Metarhizium brunneum. Founding queens showed a similar preference for the related but non-entomopathogenic fungus Fusarium graminearum. In contrast, founding queens had no significant preference for the more distantly related nonentomopathogenic fungus Petromyces alliaceus, nor for heat-killed spores of B. bassiana. Finally, founding queens did not increase the rate of queen association in presence of B. bassiana. The surprising preference of founding queens for nest sites contaminated by live entomopathogenic fungi suggests that parasites manipulate their hosts or that the presence of specific fungi is a cue associated with suitable nesting sites.

Mast cells are dispensable for normal and activin-promoted wound healing and skin carcinogenesis.

The growth and differentiation factor activin A is a key regulator of tissue repair, inflammation, fibrosis, and tumorigenesis. However, the cellular targets, which mediate the different activin functions, are still largely unknown. In this study, we show that activin increases the number of mature mast cells in mouse skin in vivo. To determine the relevance of this finding for wound healing and skin carcinogenesis, we mated activin transgenic mice with CreMaster mice, which are characterized by Cre recombinase-mediated mast cell eradication. Using single- and double-mutant mice, we show that loss of mast cells neither affected the stimulatory effect of overexpressed activin on granulation tissue formation and reepithelialization of skin wounds nor its protumorigenic activity in a model of chemically induced skin carcinogenesis. Furthermore, mast cell deficiency did not alter wounding-induced inflammation and new tissue formation or chemically induced angiogenesis and tumorigenesis in mice with normal activin levels. These findings reveal that mast cells are not major targets of activin during wound healing and skin cancer development and also argue against nonredundant functions of mast cells in wound healing and skin carcinogenesis in general.

Task-dependent influence of genetic architecture and mating frequency on division of labour in social insect societies.

Division of labour is one of the most prominent features of social insects. The efficient allocation of individuals to different tasks requires dynamic adjustment in response to environmental perturbations. Theoretical models suggest that the colony-level flexibility in responding to external changes and internal perturbation may depend on the within-colony genetic diversity, which is affected by the number of breeding individuals. However, these models have not considered the genetic architecture underlying the propensity of workers to perform the various tasks. Here, we investigated how both within-colony genetic variability (stemming from variation in the number of matings by queens) and the number of genes influencing the stimulus (threshold) for a given task at which workers begin to perform that task jointly influence task allocation efficiency. We used a numerical agent-based model to investigate the situation where workers had to perform either a regulatory task or a foraging task. One hundred generations of artificial selection in populations consisting of 500 colonies revealed that an increased number of matings always improved colony performance, whatever the number of loci encoding the thresholds of the regulatory and foraging tasks. However, the beneficial effect of additional matings was particularly important when the genetic architecture of queens comprised one or a few genes for the foraging task's threshold. By contrast, a higher number of genes encoding the foraging task reduced colony performance with the detrimental effect being stronger when queens had mated with several males. Finally, the number of genes encoding the threshold for the regulatory task only had a minor effect on colony performance. Overall, our numerical experiments support the importance of mating frequency on efficiency of division of labour and also reveal complex interactions between the number of matings and genetic architecture.

A review of coccidiostat residues in poultry

safefood, the Food Safety Promotion Board, is responsible for increasing food safety awareness and for supporting north/south scientific co-operation. safefood is currently funding a project entitled "Poultry Meat: improving food safety by improving chemical residue surveillance". This joint project between the Veterinary Sciences Division, Queen's University, Belfast and the National Food Centre, Teagasc, Dublin, is addressing the problem of anti-coccidial drug residues in poultry meat and eggs through an all-island research and residue testing initiative. The project started in 2001 and will continue until 2004. Poultry have a high susceptibility to the parasitic disease, coccidiosis. Because of this susceptibility, veterinary drugs, commonly known as coccidiostats are routinely used in intensively-reared poultry. The coccidiostats are potent drugs and, where residues occur in food, they may exacerbate certain coronary disease conditions. It is important, therefore, for poultry and egg producers to prevent the occurrence of residues of coccidiostats in food products.

Immune priming and pathogen resistance in ant queens.

Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring.

Inequalities in Old Age: The impact of the recession on older people in Ireland, North and South CARDI Grants

Inequalities in Old Age: the impact of the recession on older people in Ireland, North and SouthAbout the research:This research, led by Professor Paddy Hillyard, Emeritus Professor Queen’s University Belfast, was carried out with funding from CARDI’s Grants Programme Call 2. The purpose of the study was to analyse the impact of the recession on older people in Northern Ireland (NI) and the Republic of Ireland (ROI) and the extent to which inequalities within the older population have been affected by the economic crisis.Research Brief:This brief, authored by CARDI staff, is based on the findings of the research project and also contains additional information of interest.Research Team:Professor Paddy Hillyard, Emeritus Professor Queen’s University Belfast - lead researcher;Dr Francesca Lundstr̦m, Research Consultant;Dr Demi Patsios, Policy Research Consultant;Sarah Machniewski, Researcher;David Taylor, Chartered Accountant and Management Consultant;Dr Maureen Lyons, Research Manager, School of Social Justice, UCD.Methodology and availability of data:Several methods were used in the research, including:�� a review of relevant literature;����a detailed analysis of many databases relevant to older people’s incomes and lives;��building a model to assess the impact of the recession on older people;surveys of financial advisers in voluntary, private and public sectors;��six focus groups, three each in NI and RoI.Availability of data:Despite the huge amount of information which is officially collected and published in NI and RoI, very little is directly comparable. ��The development of a mechanism to encourage the production of more comparable data North and South would be very beneficial.��For example, this study identified a basket of 25 factors that can be used to compare the living standards of older people in NI and RoI and to monitor changes in future yearsTo access the full report please click on the following link:Inequalities in Old Age: the impact of the recession on older people in Ireland, North and SouthPlease find the presentation from the launch below:Inequalities, Pensions and the Recession by Prof Paddy Hillyard, Queen’s University Belfast and Dr Demi Patsios, Policy Research Consultant, Dr Francesca Lundstr̦m, Research Consultant.��������

Inequalities in old age - old news or new debate: Presentations

On October 20th, 2010, CARDI hosted an event entitled��'Inequalities in old age - old news or new debate?’. The event marked the launch of a CARDI funded research report Inequalities in Old Age: the impact of the recession on older people in Ireland, North and South��and the launch of a discussion paper prepared for CARDI by Dr. Maria Pierce and Dr.��Virpi Timonen, Trinity College Dublin��Theories of Ageing and Approaches to Welfare in Ireland, North and South [summary]. The event also featured a number of other presentations. Please find a selection of the presentations from the day below:Theories of Ageing: Lenses for Understanding, Signposts for Reforming Social Protection in Old Age by Dr Virpi Timonen, Director of SPARC and Dr Maria Pierce, Research Fellow, Trinity College Dublin.Inequalities, Pensions and the Recession by Prof Paddy Hillyard, Queen’s University Belfast and Dr Demi Patsios, Policy Research Consultant, Dr Francesca Lundstr̦m, Research Consultant.Pensions and Older Women by Dr Aine N�_ L̩ime, Programme Co-ordinator, ICSG (Irish Centre for Social Gerontology), NUI Galway.����

Physical activity and mental health in ageing

This research brief examines the links between maintaining recommended levels of physical activity and positive effects on mental health and brain functioning as well as the public policy strategies in place to promote physical activity in the older population. It is based on three CARDI-funded projects:- Physical activity and core depressive symptoms in the older Irish adult population, led by Karen Morgan at the Royal College of Surgeons in Ireland.- Using aerobic exercise to promote brain plasticity, conducted by Richard Carson at Queen’s University, Belfast.- Leading dance for older people, led by Sylvia O’Sullivan at the University of Limerick.

CARDI Research Brief: Medication use in patients with dementia at the end of life

��Palliative care and medication use are important issues in dealing with end-of-life stage dementia. As research into palliative care for patients with advanced dementia has been limited to date, CARDI funded a project, led by Dr. Carole Parsons of Queen’s University Belfast, as part of its grants programme. This project aimed to evaluate the extent to which patient-related factors influenced clinical decision-making with regard to medication use in patients with endstagedementia. This research brief presents a summary of the findings from the full report, Assessment of factors which influence physician decisionmaking regarding medication use in patients with dementia at the end of life (Parsons, et al., 2012).Read the research brief here: Medication use in patients with dementia at the end of lifeRead the press release here

An exploratory study of the wealth of older people in Ireland ��� North and South

In 2012, CARDI was asked by The Office of the First Minister and Deputy First Minister in Northern Ireland to carry out a series of research projects on ageing in Ireland, North and South. This study, An exploratory study of the wealth of older people in Ireland – North and South, was led by Professor Paddy Hillyard, Queen's University Belfast. It had the following objectives: Examine what information is available on the wealth of older people on the island of Ireland. Describe the type and level of housing, property and other assets. Provide comparable estimates of the wealth of older people in Northern Ireland (NI) and the Republic of Ireland (ROI). Draw out the policy implications of the research. Stimulate a wider discussion about wealth and inequalities. Key findings: In NI the total personal wealth was estimated at just under �100 billion. People aged 50 and under were estimated to have 35% of the total wealth, while people aged 50 and over had 65%. Existing data does not allow for a similar comparison in ROI. People aged 65+ in NI have a median disposable weekly income of �280 compared to �494 for those aged 25-49, �452 for those aged 50-64 and �251 for those aged 16-24. In ROI, people aged 65+ have a median disposable weekly income of €446 compared to €790 for those aged 25-49, €654 for those aged 50-64 and €418 for those aged 16-24. In NI, people aged 65+ have the highest rate of home ownership (63%) and the lowest level of outstanding mortgage (3%) of any age group. They also have the highest level of savings (�4,000 on average) but the lowest level of value of household goods (a median of �525). In ROI, 87% of people over 65 own their house outright and 2% own their house with a mortgage. The average value of savings held by this age group is €5,519. In ROI the total value of owner-occupied housing stock was estimated to be €280 billion, of which 54% was held by those under 50. In NI people over 50 had �42.5 billion (60%) of owner-occupied housing assets while those under 50 had �28.2 billion (40%).

Social structure varies with elevation in an Alpine ant.

Insect societies vary greatly in social organization, yet the relative roles of ecological and genetic factors in driving this variation remain poorly understood. Identifying how social structure varies along environmental gradients can provide insights into the ecological conditions favouring alternative social organizations. Here, we investigate how queen number variation is distributed along elevation gradients within a socially polymorphic ant, the Alpine silver ant Formica selysi. We sampled low- and high-elevation populations in multiple Alpine valleys. We show that populations belonging to different drainage basins are genetically differentiated. In contrast, there is little genetic divergence between low- and high-elevation populations within the same drainage basin. Thus, elevation gradients in each of the drainage basins represent independent contrasts. Whatever the elevation, all well-sampled populations are socially polymorphic, containing both monogynous (= one queen) and polygynous (= multiple queen) colonies. However, the proportion of monogynous colonies per population increases at higher elevation, while the effective number of queens in polygynous colonies decreases, and this pattern is replicated in each drainage basin. The increased prevalence of colonies with a single queen at high elevation is correlated with summer and winter average temperature, but not with precipitation. The colder, unpredictable and patchy environment encountered at higher elevations may favour larger queens with the ability to disperse and establish incipient monogynous colonies independently, while the stable and continuous habitat in the lowlands may favour large, fast-growing polygynous colonies. By highlighting differences in the environmental conditions favouring monogynous or polygynous colonies, this study sheds light on the ecological factors influencing the distribution and maintenance of social polymorphism.

Reproductive conflicts and egg discrimination in a socially polymorphic ant

The ability to discriminate against competitors shapes cooperation and conflicts in all forms of social life. In insect societies, workers may detect and destroy eggs laid by other workers or by foreign queens, which can contribute to regulate reproductive conflicts among workers and queens. Variation in colony kin structure affects the magnitude of these conflicts and the diversity of cues used for discrimination, but the impact of the number of queens per colony on the ability of workers to discriminate between eggs of diverse origin has so far not been investigated. Here, we examined whether workers from the socially polymorphic ant Formica selysi distinguished eggs laid by nestmate workers from eggs laid by nestmate queens, as well as eggs laid by foreign queens from eggs laid by nestmate queens. Workers from single- and multiple-queen colonies discriminated worker-laid from queen-laid eggs, and eliminated the former. This suggests that workers collectively police each other in order to limit the colony-level costs of worker reproduction and not because of relatedness differences towards queens' and workers' sons. Workers from single-queen colonies discriminated eggs laid by foreign queens of the same social structure from eggs laid by nestmate queens. In contrast, workers from multiple-queen colonies did not make this distinction, possibly because cues on workers or eggs are more diverse. Overall, these data indicate that the ability of F. selysi workers to discriminate eggs is sufficient to restrain worker reproduction but does not permit discrimination between matrilines in multiple-queen colonies.