News Article | January 26, 2016
While this event was first predicted almost twenty years ago, evidence for it has proved elusive. Now, researchers from the University of Glasgow have demonstrated the Meselson effect for the first time in any organism at a genome-wide level, studying a parasite called Trypanosoma brucei gambiense (T.b. gambiense). Their findings are to be published in the journal eLife. The research was conducted at the Wellcome Trust Centre for Molecular Parasitology in the University's Institute of Biodiversity Animal Health and Comparative Medicine. T.b. gambiense is responsible for causing African sleeping sickness in humans, leading to severe symptoms including fever, headaches, extreme fatigue, and aching muscles and joints, which do not occur until weeks or sometimes even months after infection. These symptoms extend to neurologic problems, such as progressive confusion and personality changes, when the infection invades the central nervous system. In order to demonstrate the Meselson effect in T.b. gambiense, the research team, led by Dr. Annette Macleod, sequenced the genomes of 85 isolates of the parasite, including multiple samples from disease focus points within Guinea, Cote d'Ivoire and Cameroon, collected over fifty years from 1952 to 2004. The similarity of the genomes studied from these different locations, together with a lack of recombination in the evolution of the parasite, suggests that this sub-species emerged from a single individual within the last 10,000 years. "It was around this time that livestock farming was developing in West Africa, allowing the parasite, which was originally an animal organism, to 'jump' from one species to the other via the Tsetse fly," says lead author Dr. Willie Weir. "Since then, mutations have built up and the lack of sexual recombination in T.b. gambiense means that the two chromosomes in each pair have evolved independently of each other, demonstrating the Meselson effect." Dr. Weir adds that the parasites' inability to recombine with each other prevents genes from being exchanged between strains. This could subsequently hamper the ability of the organism to develop resistance to multiple drugs. The team also uncovered evidence that the parasite uses gene conversion to compensate for its lack of sex. This mechanism essentially repairs the inferior, or mutated, copy of a gene on a chromosome by 'copying and pasting' the superior copy from the chromosome's partner. The future challenge will be to investigate the effectiveness of this mechanism in the long term, as evolutionary theory suggests that asexual organisms should eventually face extinction. If T.b. gambiense shares this fate, the major cause of African sleeping sickness will be eliminated - although it is impossible to predict when this might happen. Explore further: Sequence is scaffold to study sleeping sickness More information: William Weir et al. Population genomics reveals the origin and asexual evolution of human infective trypanosomes, eLife (2016). DOI: 10.7554/eLife.11473
Gabriel D.,University of Leeds |
Gabriel D.,Julius Kuhn Institute |
Gabriel D.,Institute of Biodiversity |
Sait S.M.,University of Leeds |
And 2 more authors.
Journal of Applied Ecology | Year: 2013
A substantial proportion of the global land surface is used for agricultural production. Agricultural land serves multiple societal purposes; it provides food, fuel and fibre and also acts as habitat for organisms and supports the services they provide. Biodiversity conservation and food production need to be balanced: production needs to be sustainable, while conservation cannot be totally at the expense of crop yield. To identify the benefits (in terms of biodiversity conservation) and costs (in terms of reduction in yields) of agricultural management, we examined the relationship between crop yield and abundance and species density of important taxa in winter cereal fields on both organic and conventional farms in lowland England. Of eight species groups examined, five (farmland plants, bumblebees, butterflies, solitary bees and epigeal arthropods) were negatively associated with crop yield, but the shape of this relationship varied between taxa. It was linear for the abundance of bumblebees and species density of butterflies, concave up for the abundance of epigeal arthropods and butterflies and concave down for species density of plants and bumblebees. Grain production per unit area was 54% lower in organic compared with conventional fields. When controlling for yield, diversity of bumblebees, butterflies, hoverflies and epigeal arthropods did not differ between farming systems, indicating that observed differences in biodiversity between organic and conventional fields are explained by lower yields in organic fields and not by different management practices per se. Only percentage cover and species density of plants were increased by organic field management after controlling for yield. The abundance of solitary wild bees and hoverflies was increased in landscapes with high amount of organic land. Synthesis and applications. Our results indicate that considerable gains in biodiversity require roughly proportionate reductions in yield in highly productive agricultural systems. They suggest that conservation efforts may be more cost effective in low-productivity agricultural systems or on non-agricultural land. In less productive agricultural landscapes, biodiversity benefit can be gained by concentrating organic farms into hotspots without a commensurate reduction in yield. Our results indicate that considerable gains in biodiversity require roughly proportionate reductions in yield in highly productive agricultural systems. They suggest that conservation efforts may be more cost effective in low-productivity agricultural systems or on non-agricultural land. In less productive agricultural landscapes, biodiversity benefit can be gained by concentrating organic farms into hotspots without a commensurate reduction in yield. © 2013 British Ecological Society.
News Article | December 2, 2016
The group has published their findings in a study today in the Journal of Fish Diseases, including data showing that a simple measurement procedure could be used to detect Atlantic salmon infected with salmonid alpha virus, which causes pancreas disease. Pancreas disease – which is not an issue for product consumption and is harmless to humans – can cause significant losses in farmed Atlantic salmon due to morbidity, mortality and reduced production. The researchers found that salmon with pancreas disease had a major change in the proteins present in the blood, and further to that, that these protein changes could be detected using a simple procedure. The test, called a selective precipitation reaction (SPR), has been patented by the team and could potentially be developed into a rapid analysis system allowing the disease to be diagnosed much earlier than is currently possible. This would mean that the test could be applied at a fish farm, allowing for quick diagnosis of the disease and early treatment. Current testing requires sample submissions being sent to laboratories, a process that can take several days before results are available. Professor David Eckersall, Professor of Veterinary Biochemistry and leader of the research team at the Institute of Biodiversity, Animal Health and Comparative Medicine, said: "The serendipitous discovery of the SPR has allowed a potentially powerful diagnostic test to be developed that could have significant applications in the future. "This collaborative study, funded by a BBSRC CASE PhD studentship for our colleague Mark Braceland and supported by the aquaculture industry, has made a major contribution to the health and welfare of salmon. If this SPR test can be applied to other diseases and species of fish then the benefit will be even greater. This is an excellent example of the benefit of academia-industry links supported by the BBSRC CASE studentship scheme." Pancreas disease can, according to Aunsmo et al (2012), cause a loss of up to £1.43m for a single fish farm, so early detection is a vital component of the health care of salmon in aquaculture. The SPR test may also be useful in detecting other salmon diseases, or even diseases in other fish. Dr Mark Braceland, who now is in Prince Edward Island (Canada) at the Center for Aquaculture Technologies, said: "One of the persistent challenges faced by the industry is monitoring of stocks and defining what healthy stocks are. Marine aquaculture is a very unique and relatively new form of livestock culture, and as such, diagnostic and prognostic tools available for this industry are lacking. "The SPR has some great potential in complementing pathogen screening by allowing the industry to identify clinical stages of disease process, thus giving valuable information for health practitioners. I also see it as a valuable tool for establishing the efficacy of treatment and disease prevention technologies and hope it shall be utilized in this way in the future." Dr John Tinsley of BioMar Ltd said: "The collaboration with Professor Eckersall and the University of Glasgow has been a great success and we would like it to continue. The project not only developed a highly applicable diagnostic test for the industry, but produced numerous peer reviewed articles and advanced our knowledge of fish health and welfare." Dr Dave Cockerill (MRCVS) of Marine Harvest (Scotland) Ltd said: "SPR gives us an opportunity to put in place an early warning system for detection of significant pathology in fish. In particular it appears to be a non-specific indicator of this type of disease and this sets it apart from other diagnostic tools which test for specific known disease agents. SPR could become the early indicator that further specific investigation is required." More information: 'Selective Precipitation Reaction: A Novel Diagnostic Test for Tissue Pathology in Atlantic Salmon, Salmo salar, infected with Salmonid Alpha-Virus,' Journal of Fish Diseases
News Article | December 2, 2015
The new findings, based on wild house sparrows, and published today, show how changes in DNA that are linked to ageing and lifespan take place as body size gets bigger. Although larger types of animals tend to live longer than smaller ones – elephants live longer than mice – within many species the bigger individuals have shorter life spans than their smaller counterparts – a Jack Russell has a much longer life than a St Bernard. In humans, a recent study has shown that taller people are more prone to diseases including cancer. But biologists haven't been able to fully explain why. Research into telomeres, special DNA structures that all animals have at the ends of their chromosomes, described as functioning like "the protective plastic caps at the end of shoelaces" may provide the answer. The study, conducted jointly by the University of Glasgow's Institute of Biodiversity, Animal Health & Comparative Medicine and the Centre of Biodiversity Dynamics at the Norwegian University of Science and Technology, focused on a population of wild house sparrows on the isolated island of Leka in Norway. The research, published in the Proceedings of the Royal SocietyB: Biological Sciences, found that skeletally bigger house sparrows had shorter telomeres. This relationship was maintained during a period when a selective breeding programme on the island resulted in the sparrows becoming even larger. In tandem, their telomeres became even shorter. Everyone's telomeres erode over time, and telomere shortening has been linked to ageing and disease risk including cancer. Having naturally longer telomeres appears to give individuals an advantage when it comes to health and the biological aging process. The results shed light on a paradox that has puzzled biologists for a long time. If being bigger gives you a competitive advantage, why don't animals just get bigger and bigger? Part of the answer is that growing big can mean more telomere loss and faster ageing. Professor Pat Monaghan, Regius Chair of Zoology at the University of Glasgow, who supervised the telomere analysis, said: "Growing a bigger body means that cells have to divide more. As a result, telomeres become eroded faster and cells and tissues function less well as a result. "The reason why the bigger individuals have shorter telomeres might also be related to increased DNA damage due to growing faster. Being big can have advantages, of course, but this study shows that it can also have costs." Associate professor in population ecology Thor Harald Ringsby at Norwegian University of Science and Technology who was running the fieldwork together with his colleagues in Norway said: 'The results from this study are very exciting and broad reaching. It is especially interesting that we obtained these results in a natural population. The reduction in telomere size that followed the increase in body size suggests one important mechanism that limits body size evolution in wild animal populations" The study, entitled 'On being the right size: increased body size is associated with reduced telomere length under natural conditions' is published in the Proceedings of the Royal Society B: Biological Sciences journal. The research was funded by the European Research Council and the Research Council of Norway. Explore further: Researchers show telomere lengths predict life expectancy in the wild More information: On being the right size: increased body size is associated with reduced telomere length under natural conditons, Proceedings of the Royal Society B: Biological Sciences, rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2015.2331
Kostner B.,TU Dresden |
Wenkel K.-O.,Leibniz Center for Agricultural Landscape Research |
Berg M.,Leibniz Center for Agricultural Landscape Research |
Bernhofer C.,TU Dresden |
And 2 more authors.
European Journal of Agronomy | Year: 2014
One of the most decisive natural framework conditions of agriculture - the regional climate - is in transition. This requires considering climate change and climate change impact for decision making. Although this knowledge is uncertain and depends on future green-house gas emission, it is rapidly expanding and improving. Therefore, it is important to create flexible systems with adaptable data bases and analytical tools to integrate knowledge of future climate change in agronomy for impact studies and adaptation planning. The joint project LandCaRe (Land, Climate, and Resources) 2020 aimed at developing a conceptual framework and prototype of a model-based decision support system (DSS) based on improved process knowledge and stakeholder communication. The final product, the LandCaRe DSS should combine grid-based information on regional climate and land surface, robust climate impact models and socio-economic boundary conditions to develop spatially explicit climate impact scenarios. Emphasis was put on the integration of different knowledge from science and practice. Climate projections had to be adapted to the needs of impact modelling of agricultural and ecological processes at regional and farm scale. Impact modelling included new process knowledge, especially related to the CO2 fertilisation effect on crop rotations. A new Free Air Carbon Dioxide Enrichment Experiment (FACE) on the C4 plant maize was conducted during the project. A new agro-ecosystem model was developed which integrates soil-plant-atmosphere exchange and plant production to predict crop yield as well as water, carbon and nitrogen fluxes. Stakeholders included representatives of agricultural and environmental administrations, managers of agro-enterprises and large farms as well as organisations for regional planning and nature conservation. Their central common interests were future land use, water availability and management. Stakeholders from agriculture requested not only to assess potential impacts of regional climate change on yield but also to interpret climate impact on farm economy. This required the design of a farm-economy module linking effects of management and adaptation on crop yield with scenarios of costs and prices. Here an introduction to the project, components of the DSS and its further perspectives are presented. © 2013 Elsevier B.V.
Marasco V.,Institute of Biodiversity |
Robinson J.,Institute of Biodiversity |
Herzyk P.,University of Glasgow |
Spencer K.A.,Institute of Biodiversity |
Spencer K.A.,University of St. Andrews
Journal of Experimental Biology | Year: 2012
Developmental stress can significantly influence physiology and survival in many species. Mammalian studies suggest that preand post-natal stress can have different effects (i.e. hyper- or hypo-responsiveness) on the hypothalamic-pituitary-adrenal (HPA) axis, the main mediator of the stress response. In mammals, the physiological intimacy between mother and offspring constrains the possibility to control, and therefore manipulate, maternal pre- and post-natal influences. Here, using the Japanese quail (Coturnix coturnix japonica) as our model, we elevated levels of the glucocorticoid stress hormone corticosterone in ovo and/or in the endogenous circulation of hatchlings. We examined the effects of treatments on corticosterone and glucose stress responses at two different ages, in juvenile and adult quail. In juveniles, corticosterone data revealed a sex-specific effect of postnatal treatment regardless of the previous pre-natal protocol, with post-natally treated females showing shorter stress responses in comparison with the other groups, while no differences were observed among males. In adulthood, birds previously stressed as embryos showed higher corticosterone concentrations over the stress response compared with controls. This effect was not evident in birds subjected to either post-natal treatment or the combined treatments. There were no effects on glucose in the juveniles. However, adult birds previously stressed in ovo showed opposite sex-specific basal glucose patterns compared with the other groups. Our results demonstrate that (1) early glucocorticoid exposure can have both transient and long-term effects on the HPA axis, depending upon the developmental stage and sex and (2) post-natal stress can modulate the effects of pre-natal stress on HPA activity. © 2012. Published by The Company of Biologists Ltd.
Anderson T.-H.,Institute of Agroecology |
Anderson T.-H.,Institute of Biodiversity |
Heinemeyer O.,Institute of Agroecology |
Heinemeyer O.,Institute of Agricultural Climate Research |
And 2 more authors.
Soil Biology and Biochemistry | Year: 2011
In soil ecology, microbial parameters have been identified as sensitive indicators of changes in the soil environment. The Braunschweig FACE project provided the opportunity to study the effects of elevated CO2 (550 μmol mol-1) as compared to ambient CO2 (370 μmol mol-1) on total microbial biomass (Cmic), Cmic-to-Corg ratio and the fungal-to-bacterial respiratory ratio together with total Corg, Nt, C:N ratio and pH over a six-year period. Field management followed a typical crop rotation system of this region with either a crop-related full nitrogen supply (N100) or 50% reduced N supply (N50). The soil microbial parameters responded to the elevated CO2 treatment in varying intensities and time spans. The fungal-to-bacterial respiratory ratio was the most sensitive parameter in responding to an elevated CO2 treatment with highly significant differences to ambient CO2-treated control plots in the third year of CO2 fumigation. After six years bacterial respiratory activity had increased in ascending order to 34% in FACE-treated plots (N50 and N100) as compared to control plots. Soil microbial biomass (Cmic) responded more slowly to the FACE treatment with highly significant increases of >12% after the fourth year of CO2 fumigation. The Cmic-to-Corg ratio responded very late in the last two years of the CO2 treatment with a significant increase of >7.0% only in the N100 variant. Total Corg and Nt were slightly but significantly increased under FACE around 10.0% with ascending tendency over time starting with the second year of CO2 treatment. No significant FACE effects could be recorded for the C:N ratio or pH.These results suggest that under FACE treatment changes in the soil microbial community will occur. In our study the fungal-to-bacterial respiratory ratio was superior to total Cmic as microbial bioindicators in reflecting changes in the soil organic matter composition. © 2011 Elsevier Ltd.
Anderson T.-H.,Institute of Agroecology |
Anderson T.-H.,Institute of Agricultural Climate Research |
Martens R.,Institute of Agroecology |
Martens R.,Institute of Biodiversity
Soil Biology and Biochemistry | Year: 2013
We attempted to quantify microbial growth in soil by means of DNA determination after glucose amendment. An FDNA conversion factor of 5.0 was used to convert μg DNA g-1 soil to μg Cmic g-1 soil during the growth phase. The conversion factor acquired rested on a regression analysis between soil microbial biomass-C (Cmic) estimated by the substrate-induced respiration technique (SIR) and dsDNA using a modified, miniaturized dsDNA extraction procedure which included 44 field and forest soils with a coefficient of determination of r2 = 0.95. Verification of this conversion factor was tested on eight arable soils where Cmic was determined by substrate-induced respiration (SIR)-, chloroform fumigation-incubation (CFI)-, chloroform fumigation-extraction (CFE)-, and application of the FDNA conversion factor. The congruency between the Cmic values obtained through these different techniques was satisfactory since five of eight soils gave similar Cmic values which were not statistically significantly different. The soils were thereafter amended with glucose and microbial growth followed by Cmic determinations with CFI, CFE, and DNA conversion over a period of up to 264 h at 22 °C. Concomitant CO2 analyses gave clues to two kinds of growth processes with respect to speed. Based on DNA conversion the calculated traditional growth parameters such as the specific growth rate (μ) lay in the range between 0.0046 and 0.022 h-1 which is several fold slower than μ values based on CO2 conversion but are in accordance with data in the earlier literature on growth rates for bacteria and fungi in soil done with traditional plate counts. These results suggest that DNA determinations can be applied as an alternative index for growth studies in situ. © 2012 Elsevier Ltd.
Solomon S.E.,Institute of Biodiversity |
Bain M.M.,Institute of Biodiversity
British Poultry Science | Year: 2012
1. An experiment was designed to determine whether the inclusion of sodium selenite, Sel-Plex or Sel-plex + Bioplex in the diet exerted any influence on structural and functional properties of the eggshell at 22, 38, 58 and 72 weeks age.2. Significant age effects were demonstrated for egg weight, dynamic stiffness and total shell thickness.3. The eggshells from birds fed on the Sel-Plex + Bioplex treatment were statistically stronger than those produced by the birds on sodium selenite.4. From mid-lay onwards the shells laid by birds fed on the Sel-Plex + Bioplex treatment displayed, at ultrastructural level, the crystal modification termed 'confluence' together with early fusion of the palisade columns which comprised the bulk of the shell.5. At all periods of lay the shells of birds fed on sodium selenite, Sel-Plex and the control diet demonstrated the presence of a variety of crystalline aggregates localised between the forming palisade columns. © 2012 Copyright Taylor and Francis Group, LLC.
Wamsera S.,Justus Liebig University |
Dauber J.,Institute of Biodiversity |
Birkhofer K.,Justus Liebig University |
Wolters V.,Justus Liebig University
Agriculture, Ecosystems and Environment | Year: 2011
The colonisation of winter barley fields by spring breeding carabids and its temporal modulation by the amount of potential hibernation sites was studied. Species richness of carabids was lower in landscapes with high length of boundaries and a high amount of non-cropped open habitats during early stages of the beetles' colonisation of arable fields. Species number of beetles with high dispersal potential responded to this landscape features at coarse spatial scales whereas beetles with low dispersal potential responded to intermediate scales. However, the negative impact of potential hibernation sites on colonisation diminished in later sampling phases. The patterns observed may be explained by both overwintering in arable soils in less complex landscapes and delayed colonisation in more complex landscapes. The seasonal patterns of landscape control suggest a need to account for temporal dynamics in interactions between species or functional groups and landscape properties. A high temporal resolution is needed in studies that focus on ecosystem function and services in agricultural landscapes, as direction of effect (positive/ negative) of management on animal communities may change across spatial scales and within short time periods. © 2011 Elsevier B.V.