• Agrobacterium-mediated transformation and insertional mutagenesis in colletotrichum acutatum for investigating varied pathogenicity lifestyles

      Talhinhas, Pedro; Muthumeenakshi, S.; Neves-Martins, João; Oliveira, Helena; Sreenivasaprasad, Surapareddy; Technical University of Lisbon; University of Warwick (Humana Press, 2008)
      Colletotrichum acutatum is a cosmopolitan pathogen causing economically important diseases known as anthracnose on a wide range of hosts. This fungus exhibits varied pathogenicity lifestyles and the tools essential to understand the molecular mechanisms are still being developed. The transformation methods currently available for this species for gene discovery and functional analysis involve protoplast transformation and are laborious and inefficient. We have developed a protocol for efficient Agrobacterium tumefaciens-mediated transformation (ATMT) of C. acutatum. Using this protocol we were able to transform C. acutatum isolates belonging to different genetic groups and originating from different hosts. The transformation efficiency was up to 156 transformants per 10(4) conidia, with >70% transformants showing single location/single copy integration of T-DNA. Binary vector pBHt2-GFP was constructed, enabling green fluorescence protein tagging of C. acutatum strains, which will be a useful tool for epidemiology and histopathology studies. The ATMT protocol developed was used to identify putative pathogenicity mutants, suggesting the applicability of this technique for rapid generation of a large panel of insertional mutants of C. acutatum leading to the identification of the genes associated with the varied lifestyles.
    • Bring the captive closer to the wild: redefining the role of ex situ conservation

      Pritchard, Diana J.; Fa, John E.; Oldfield, Sara; Harrop, Stuart R.; University of Sussex; Durrell Wildlife Conservation Trust; Imperial College London; Botanical Gardens Conservation International; University of Kent (Wiley Blackwell, 2011)
      In situ conservation is central to contemporary global biodiversity protection and is the predominant emphasis of international regulation and funding strategies. Ex situ approaches, in contrast, have been relegated to a subsidiary role and their direct contributions to conservation have been limited. We draw on a variety of sources to make the case for an enhanced role for ex situ conservation. We note the advances occurring within institutions specializing in ex situ conservation and stress that, although much remains to be done, many constraints are being addressed. We argue that the evidence of increasing extinction rates, exacerbated by climate change, challenges the wisdom of a heavy dependence on in situ strategies and necessitates increased development of ex situ approaches. A number of different techniques that enable species and their habitats to survive should now be explored. These could build on the experience of management systems that have already demonstrated the effective integration of in situ and ex situ techniques and hybrid approaches.
    • Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005

      Eakin, C. Mark; Morgan, Jessica A.; Heron, Scott F.; Smith, Tyler B.; Liu, Gang; Alvarez-Filip, Lorenzo; Baca, Bart; Bartels, Erich; Bastidas, Carolina; Bouchon, Claude; et al. (Public Library Science, 2010-11-15)
    • Challenges for sustainability in cultures where regard for the future may not be present

      Crabbe, M. James C. (ProQuest, 2006)
      A concept of time depends upon both culture and linguistics, and one person’s future may be another person’s present. Temporal and spatial concepts are crucial to sustainability issues and a concept of “the future” may depend upon ethnicity, linguistic background, lifestyle, and life expectancy. Many currently threatened natural systems are in locations where the indigenous people have a linguistic and conceptual background very different from those in the so-called developed countries. One example is the Bajau people who live off the southeast coast of Sulawesi in Indonesia, close to highly endangered coral reefs. How can we connect the “future perspective” mismatch between Austronesian people like the Bajau and conservationists from developed countries who want to protect the reefs for future generations? Many challenges are ahead, not the least being a practical one of providing the right education for the Bajau to show how certain actions – for example, “no-take” fishing zones – can help achieve their aspirations. Perhaps even more important is the moral challenge of reassessing our own assumptions about worthwhile aspirations, about what is good for the Bajau – and similar people – and their rights and roles in determining the outcomes.
    • Climate change and tropical marine agriculture

      Crabbe, M. James C. (Oxford University Press, 2009)
      The coral reef ecosystem forms part of a ‘seascape’ that includes land-based ecosystems such as mangroves and forests, and ideally should form a complete system for conservation and management. Aquaculture, including artisanal fishing for fish and invertebrates, shrimp farming, and seaweed farming, is a major part of the farming and gleaning practices of many tropical communities, particularly on small islands, and depends upon the integrity of the reefs. Climate change is making major impacts on these communities, not least through global warming and high CO2 concentrations. Corals grow within very narrow limits of temperature, provide livelihoods for millions of people in tropical areas, and are under serious threat from a variety of environmental and climate extremes. Corals survive and grow through a symbiotic relationship with photosynthetic algae: zooxanthellae. Such systems apply highly cooperative regulation to minimize the fluctuation of metabolite concentration profiles in the face of transient perturbations. This review will discuss research on how climate influences reef ecosystems, and how science can lead to conservation actions, with benefits for the human populations reliant on the reefs for their survival.
    • Climate change, global warming and coral reefs: modelling the effects of temperature

      Crabbe, M. James C. (Elsevier, 2008)
      Climate change and global warming have severe consequences for the survival of scleractinian (reef-building) corals and their associated ecosystems. This review summarizes recent literature on the influence of temperature on coral growth, coral bleaching, and modelling the effects of high temperature on corals. Satellite-based sea surface temperature (SST) and coral bleaching information available on the internet is an important tool in monitoring and modelling coral responses to temperature. Within the narrow temperature range for coral growth, corals can respond to rate of temperature change as well as to temperature per se. We need to continue to develop models of how non-steady-state processes such as global warming and climate change will affect coral reefs.
    • Community based biodiversity monitoring in Mexico: current status, challenges, and future strategies for collaboration with scientists

      Pritchard, Diana J. (Springer, 2013-07-18)
      An array of social and political actors, from international to local levels, increasingly demand monitoring data on biodiversity and ecosystem functions. As elsewhere, prevalent approaches in Mexico emphasize the collection of scientific data regarding biological indicators, by professionals, for conservation planning, global targets, and biological inquiry. These are complicated, expensive, and dependent on external funding. They also fail to engage with communities, many of whom practice traditional forms of monitoring to manage their local environments and livelihoods. Community-based monitoring, an approach involving collaborations between scientists and communities, has the potential to contribute to sustainable forms of resource use management and as a cost-effective method. Efforts could develop once local rights of use and traditional knowledge systems are recognized, access to information is ensured, and a broad array of relevant environmental and social indicators are included.
    • Complete chloroplast genome sequence of Holoparasite Cistanche Deserticola (Orobanchaceae) reveals gene loss and horizontal gene transfer from Its host Haloxylon Ammodendron (Chenopodiaceae)

      Li, Xi; Zhang, Ti-Cao; Qiao, Qin; Ren, Zhumei; Zhao, Jiayuan; Yonezawa, Takahiro; Hasegawa, Masami; Crabbe, M. James C.; Li, Jianqiang; Zhong, Yang; et al. (Public Library of Science, 2013)
      The central function of chloroplasts is to carry out photosynthesis, and its gene content and structure are highly conserved across land plants. Parasitic plants, which have reduced photosynthetic ability, suffer gene losses from the chloroplast (cp) genome accompanied by the relaxation of selective constraints. Compared with the rapid rise in the number of cp genome sequences of photosynthetic organisms, there are limited data sets from parasitic plants. The authors report the complete sequence of the cp genome of Cistanche deserticola, a holoparasitic desert species belonging to the family Orobanchaceae.
    • Context-dependent effects of predator removal from experimental microcosm communities

      Worsfold, Nicholas T.; Warren, Philip H.; Petchey, Owen L. (Nordic Ecological Society, 2009)
      The loss of a predator from an ecological community can cause large changes in community structure and ecosystem processes, or have very little consequence for the remaining species and ecosystem. Understanding when and why the loss of a predator causes large changes in community structure and ecosystem processes is critical for understanding the functional consequences of biodiversity loss. We used experimental microbial communities to investigate how the removal of a large generalist predator affected the extinction frequency, population abundance and total biomass of its prey. We removed this predator in the presence or absence of an alternative, more specialist, predator in order to determine whether the specialist predator affected the outcome of the initial species removal. Removal of the large generalist predator altered some species’ populations but many were unaffected and no secondary extinctions were observed. The specialist predator, though rare, altered the response of the prey community to the removal of the large generalist predator. In the absence of the specialist predator, the effects of the removal were only measurable at the level of individual species. However, when the specialist predator was present, the removal of the large generalist predator affected the total biomass of prey species. The results demonstrate that the effect of species loss from high trophic levels may be very context-dependent, as rare species can have disproportionately large effects in food webs.
    • Coral reef populations in the Caribbean: is there a case for better protection against climate change?

      Crabbe, M. James C.; University of Bedfordshire (Scientific Research Publishing, 2013-06)
      Knowledge of factors that are important in coral reef growth help us to understand how reef ecosystems react following major environmental disturbances due to climate change and other anthropogenic effects. This study shows that despite a range of anthropogenic stressors, corals on the fringing reefs south of Kingston harbour, as well as corals on fringing reefs on the north coast of Jamaica near Discovery Bay can survive and grow. Skewness values for Sidastrea siderea and Porites astreoides were positive (0.85 1.64) for all sites, implying more small colonies than large colonies. Coral growth rates are part of a demographic approach to monitoring coral reef health in times of climate change, and linear extension rates (mm.yr-1) of Acropora palmata branching corals at Dairy Bull, Rio Bueno, and Pear Tree Bottom on the north coast of Jamaica were c. 50 90 mm.year-1 from 2005-2012. The range of small-scale rugosities at the Port Royal cay sites studied was lower than that at the Discovery Bay sites; for example Rio Bueno was 1.05 ± 0.15 and Dairy Bull the most rugose at 2.3 ± 0.16. Diary Bull reef has for several years been the fringing reef with the most coral cover, with a benthic community similar to that of the 1970s. We discuss whether Jamaica can learn from methods used in other Caribbean countries to better protect its coral reefs against climate change. Establishing and maintaining fully-protected marine parks in Jamaica and elsewhere in the Caribbean is one tool to help the future of the fishing industry in developing countries. Developing MPAs as part of an overall climate change policy for a country may be the best way of integrating climate change into MPA planning, management, and evaluation.
    • Coral resilience on the reefs of Jamaica

      Crabbe, M. James C. (Society for Underwater Technology, 2011)
      Awareness of important factors for coral reef growth helps reveal how reef ecosystems react following major anthropogenic and environmental disturbances. Physical measurements by SCUBA divers, together with an underwater remotely operated vehicle (ROV), have been used to study environmental and climate effects on corals on fringing reefs in Jamaica. The period of this study, from 2002 to 2008, covers the major Caribbean-wide bleaching event of 2005. For 624 non-branching corals at Rio Bueno and Dairy Bull reef near Discovery Bay on the north coast of Jamaica, skewness values for coral populations at the two sites showed generally positive values, indicating that small colonies predominated over large colonies.
    • Cytoskeleton proteins F-actin and tubulin distribution and interaction with mitochondria in the granulosa cells surrounding stage III zebrafish (Danio rerio) oocytes

      Zampolla, Tiziana; Spikings, Emma; Rawson, David M.; Zhang, Tiantian; University of Bedfordshire (Elsevier, 2011-10-01)
      The distributional arrangement of mitochondria in the granulosa cells surrounding stage III zebrafish oocyte has been reported as a contiguous aggregation of mitochondria at the margin of the each granulosa cell. The aim of the present study was to further investigate the mitochondrial distribution in the granulosa cell layer in stage III ovarian follicles and the interaction between mitochondria and cytoskeleton elements actin and tubulin. To determine mitochondrial distribution/transport, immunocytochemistry analysis of tubulin and mitochondrial COX-I was carried out along with phalloidin staining of polymerised F-actin. The follicles were also exposed to a range of conditions that are known to affect mitochondria and the cytoskeleton proteins actin and tubulin. The mitochondrial inhibitor FCCP, the anti-mitotic drug nocodazole, and actin polymerisation inhibitor cytochalasin B were used. Levels of ATP, mtDNA copy number, and viability assessed by Trypan blue were also studied after exposure to inhibitors in order to determine the relationship between mitochondrial distribution/activity and ATP production. F-actin showed a hexagonal-polygonal distribution surrounding the mitochondria in granulosa cells, with the F-actin network adjacent to the plasma membrane of each granulosa cell. Tubulin structure presented a less organised distribution than F-actin, it was sparse in the cytosol. Interaction between mitochondria and tubulin was found indicating that mitochondria and tubulin are colocalised in zebrafish ovarian follicles. The exposure of ovarian follicles to inhibitors induced the loss of mitochondrial structural integrity showing that mitochondria distribution in granulosa cells of stage III zebrafish ovarian follicles is determined by the microtubules network.
    • Dietary glycated protein modulates the colonic microbiota towards a more detrimental composition in ulcerative colitis patients and non-ulcerative colitis subjects

      Mills, D.J.S.; Tuohy, K.M.; Booth, J.; Buck, M.; Crabbe, M. James C.; Gibson, G.R.; Ames, J.M. (Wiley-Blackwell, 2008)
      The aim of the study was to investigate the effect of native, heated and glycated bovine serum albumin (BSA) on the ulcerative colitis (UC) and non-UC colonic microbiota in vitro. Results suggest that dietary glycated protein may impact upon the composition and activity of the colonic microbiota, an important environmental variable in UC.
    • Disruption of the Coniothyrium minitans PIF1 DNA helicase gene impairs growth and capacity for sclerotial mycoparasitism

      Rogers, C.W.; Challen, M.P.; Muthumeenakshi, S.; Sreenivasaprasad, Surapareddy; Whipps, J.M. (Society for General Microbiology, 2008-06)
    • Diversity of the rice blast pathogen populations in Ghana and strategies for resistance management

      Nutsugah, S.K.; Twumasi, J.K.; Chipili, J.; Sere, Y.; Sreenivasaprasad, Surapareddy (Asian Network for Scientific Information (ANSINET), 2008)
      The present study describes the outputs of a collaborative research programme funded by the UK`s Department for International Development-Crop Protection Program to investigate the genetic (lineages) and pathogenic (pathotypes) diversity of the blast fungus populations and characterize the key sites suitable for resistance screening. Seventy-one Magnaporthe grisae isolates were collected from seven regions where rice is grown, representing blast populations in Ghana.
    • Effect of chilling on sox2, sox3 and sox19a gene expression in zebrafish (Danio rerio) embryos

      Desai, Kunjan; Spikings, Emma; Zhang, Tiantian; University of Bedfordshire (Elsevier, 2011-10)
      Zebrafish embryos have not been cryopreserved due to their structural limitations. Although embryo survival rates have been used as the measured outcome for most of the cryopreservation protocols studied, there are very limited data available at the molecular level. This study focused on the effect of chilling and subsequent warming on gene expression of sox2, sox3 and sox19a which play vital roles in the development of zebrafish embryos. A quantitative RT-PCR approach was used to investigate gene expression following chilling at 0°C for up to 180 min. The effect on gene expression was also studied during a 180 min warming period after chilling for 30 or 60 min. There were significant decreases in sox2 (up to 4-fold) and sox3 (up to 3-fold) expressions following chilling. Significant increases in gene expressions of sox2 (up to 2-fold), sox3 (up to 33-fold) and sox19a (up to 25-fold) were observed during warming in the embryos that had been chilled for 30 min. Similarly, significant increases were observed in sox2 (up to 3-fold) and sox3 (up to 2-fold) during warming in embryos that had been chilled for 60 min. These increases may be explained by compensation for the suppression observed during chilling and/or to activate repair mechanisms or maintain homeostasis.
    • Effect of methanol on mitochondrial organization in zebrafish (Danio rerio) ovarian follicles.

      Spikings, Emma; Zampolla, Tiziana; Rawson, David M.; Wang, Y.; Zhang, Tiantian; University of Bedfordshire; China Agricultural University (Elsevier, 2012-01-01)
      Successful cryopreservation is usually measured in terms of cell survival. However, there may also be more subtle effects within cells that survive. Previous studies on zebrafish have produced evidence of mitochondrial DNA (mtDNA) damage in cryopreserved embryonic blastomeres and, after exposure to cryoprotectants, alterations in mtDNA replication in embryos and decreased mitochondrial membrane potential, mtDNA and ATP production in ovarian follicles. This study shows that the decreased ATP levels previously observed in stage III zebrafish ovarian follicles exposed to ≥3 M methanol persisted in those follicles that subsequently developed to stage IV. However, the decreased mtDNA levels were restored in those follicles. In order to determine whether mitochondrial distribution and/or their transport network was affected by the methanol exposure, immunocytochemistry analysis of tubulin and mitochondrial cytochrome c oxidase I (COX-I) was performed, along with phalloidin staining of polymerized actin. Neat arrangements of all proteins were observed in control follicles, with COX-I and tubulin being colocalized near granulosa cell nuclei, while actin formed hexagonal and/or polygonal structures nearer granulosa cell membranes and projected into the oocyte surface. Exposure to methanol (2 to 4 M) disrupted the COX-I and tubulin arrangements and the hexagonal and/or polygonal actin distribution and actin projections into the oocyte. These effects were still observed in those follicles that developed to stage IV, although the severity was reduced. In summary, the disruption to function and distribution of mitochondria in ovarian follicles exposed to >2 M methanol may be mediated via disruption of the mitochondrial transport system. Some recovery of this disruption may take place after methanol removal and subsequent follicle maturation.