Public Opinion on Marine Protected Areas

The following results are based on a survey conducted by WWF-Canada to find out more about Canadians' opinions about marine protected areas

Intracellular trehalose improves osmotolerance but not desiccation tolerance in mammalian cells

AbstractTrehalose has been shown to play a role in osmotolerance or desiccation tolerance in some microorganisms, anhydrobiotic invertebrates and resurrection plants. To test whether trehalose could improve stress responses of higher eukaryotes, a mouse cell line was genetically engineered to express bacterial trehalose synthase genes. We report that the resulting levels of intracellular trehalose (∼80 mM) are able to confer increased resistance to the partial dehydration resulting from hypertonic stress, but do not enable survival of complete desiccation due to air drying

Long Term Aggresome Accumulation Leads to DNA Damage, p53-dependent Cell Cycle Arrest, and Steric Interference in Mitosis.

Juxtanuclear aggresomes form in cells when levels of aggregation-prone proteins exceed the capacity of the proteasome to degrade them. It is widely believed that aggresomes have a protective function, sequestering potentially damaging aggregates until these can be removed by autophagy. However, most in-cell studies have been carried out over a few days at most, and there is little information on the long term effects of aggresomes. To examine these long term effects, we created inducible, single-copy cell lines that expressed aggregation-prone polyglutamine proteins over several months. We present evidence that, as perinuclear aggresomes accumulate, they are associated with abnormal nuclear morphology and DNA double-strand breaks, resulting in cell cycle arrest via the phosphorylated p53 (Ser-15)-dependent pathway. Further analysis reveals that aggresomes can have a detrimental effect on mitosis by steric interference with chromosome alignment, centrosome positioning, and spindle formation. The incidence of apoptosis also increased in aggresome-containing cells. These severe defects developed gradually after juxtanuclear aggresome formation and were not associated with small cytoplasmic aggregates alone. Thus, our findings demonstrate that, in dividing cells, aggresomes are detrimental over the long term, rather than protective. This suggests a novel mechanism for polyglutamine-associated developmental and cell biological abnormalities, particularly those with early onset and non-neuronal pathologies

Plant desiccation gene found in a nematode

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A continuum model of transcriptional bursting

Transcription occurs in stochastic bursts. Early models based upon RNA hybridisation studies suggest bursting dynamics arise from alternating inactive and permissive states. Here we investigate bursting mechanism in live cells by quantitative imaging of actin gene transcription, combined with molecular genetics, stochastic simulation and probabilistic modelling. In contrast to early models, our data indicate a continuum of transcriptional states, with a slowly fluctuating initiation rate converting the gene between different levels of activity, interspersed with extended periods of inactivity. We place an upper limit of 40s on the lifetime of fluctuations in elongation rate, with initiation rate variations persisting an order of magnitude longer. TATA mutations reduce the accessibility of high activity states, leaving the lifetime of on- and off-states unchanged. A continuum or spectrum of gene states potentially enables a wide dynamic range for cell responses to stimuli

Dehydration-induced tps gene transcripts from an anhydrobiotic nematode contain novel spliced leaders and encode atypical GT-20 family proteins

Accumulation of the non-reducing disaccharide trehalose is associated with desiccation tolerance during anhydrobiosis in a number of invertebrates, but there is little information on trehalose biosynthetic genes in these organisms.We have identified two trehalose-6-phosphate synthase (tps) genes in the anhydrobiotic nematode Aphelenchus avenae and determined full length cDNA sequences for both; for comparison, full length tps cDNAs from the model nematode, Caenorhabditis elegans, have also been obtained. The A. avenae genes encode very similar proteins containing the catalytic domain characteristic of the GT-20 family of glycosyltransferases and are most similar to tps-2 of C. elegans; no evidence was found for a gene in A. avenae corresponding to Ce-tps-1. Analysis of A. avenae tps cDNAs revealed several features of interest, including alternative trans-splicing of spliced leader sequences in Aav-tps-1, and four different, novel SL1-related transspliced leaders, which were different to the canonical SL1 sequence found in all other nematodes studied. The latter observation suggests that A. avenae does not comply with the strict evolutionary conservation of SL1 sequences observed in other species. Unusual features were also noted in predicted nematode TPS proteins, which distinguish them from homologues in other higher eukaryotes (plants and insects) and in micro-organisms. Phylogenetic analysis confirmed their membership of the GT-20 glycosyltransferase family, but indicated an accelerated rate of molecular evolution. Furthermore, nematode TPS proteins possess N- and C-terminal domains, which are unrelated to those of other eukaryotes: nematode C-terminal domains, for example, do not contain trehalose-6-phosphate phosphatase-like sequences, as seen in plant and insect homologues. During onset of anhydrobiosis, both tps genes in A. avenae are upregulated, but exposure to cold or increased osmolarity also results in gene induction, although to a lesser extent. Trehalose seems likely therefore to play a role in a number of stress responses in nematodes

The majority of human CD3 epitopes are conferred by the epsilon chain

Transgenic mouse T cells expressing the human CD3ε chain bind the majority (29/36) of monoclonal antibodies (mAbs) specific for human CD3. A proportion of these mAbs are also able to recognize isolated CD3ε in a soluble, recombinant form. Thus, CD3ε can confer most CD3 epitopes on the TCR-CD3 complex, but many determinants may require assembly of the complex for their formation. A number ot mAbs did not recognize ε-transgenic T cells and probably need other CD3 subunits for binding. CD3-specific mAbs from each of the three groups defined here, as well as mAbs directed against the TCRαβ heterodimer, are all able to activate T cells. Therefore mAb attachment at several different sites on the TCR-CD3 complex can give rise to activation signals. This suggests that the cross-linking function of mitogenic antibodies may be their most significant property, rather than the perturbation of a particular ‘functional epitope

Improving post-partum family planning services provided by female community health volunteers in Nepal: a mixed methods study.

BACKGROUND: Family planning services in the post-partum period, termed post-partum family planning (PPFP) is critical to cover the unmet need for contraception, especially when institutional delivery rates have increased. However, the intention to choose PPFP methods such as post-partum intrauterine devices (PPIUD) remains low in countries such as Nepal. Community health workers such as Female Community Health Volunteers (FCHVs) could play an important role in improving the service coverage of PPFP in Nepal. However, their knowledge of PPFP and community-based services related to PPFP remain unclear. This study aims to assess the effect on community-based PPFP services by improving FCHV's knowledge through orientation on PPFP. METHODS: We conducted this mixed-methods study in Morang District in Nepal. The intervention involved orientation of FCHVs on PPFP methods. We collected quantitative data from three sources; via a survey of FCHVs that assessed their knowledge before and after the intervention, from their monthly reporting forms on counseling coverage of women at different stages of pregnancy from the communities, and by interviewing mothers in their immediate post-partum period in two selected hospitals. We also conducted six focus group discussions with the FCHVs to understand their perception of PPFP and the intervention. We performed descriptive and multivariable analyses for quantitative results and thematic analysis for qualitative data. RESULTS: In total, 230 FCHVs participated in the intervention and their knowledge of PPFP improved significantly after it. The intervention was the only factor significantly associated with their improved knowledge (adjusted odds ratio = 24, P < 0.001) in the multivariable analysis. FCHVs were able to counsel 83.3% of 1872 mothers at different stages of pregnancy in the communities. In the two hospitals, the proportion of mothers in their immediate post-partum period whom reported they were counseled by FCHVs during their pregnancy increased. It improved from 7% before the intervention to 18.1% (P < 0.001) after the intervention. The qualitative findings suggested that the intervention improved their knowledge in providing PPFP counseling. CONCLUSION: The orientation improved the FCHV's knowledge of PPFP and their community-based counseling. Follow-up studies are needed to assess the longer term effect of the FCHV's role in improving community-based PPFP services

Expression of multiple horizontally acquired genes is a hallmark of both vertebrate and invertebrate genomes.

BACKGROUND: A fundamental concept in biology is that heritable material, DNA, is passed from parent to offspring, a process called vertical gene transfer. An alternative mechanism of gene acquisition is through horizontal gene transfer (HGT), which involves movement of genetic material between different species. HGT is well-known in single-celled organisms such as bacteria, but its existence in higher organisms, including animals, is less well established, and is controversial in humans. RESULTS: We have taken advantage of the recent availability of a sufficient number of high-quality genomes and associated transcriptomes to carry out a detailed examination of HGT in 26 animal species (10 primates, 12 flies and four nematodes) and a simplified analysis in a further 14 vertebrates. Genome-wide comparative and phylogenetic analyses show that HGT in animals typically gives rise to tens or hundreds of active 'foreign' genes, largely concerned with metabolism. Our analyses suggest that while fruit flies and nematodes have continued to acquire foreign genes throughout their evolution, humans and other primates have gained relatively few since their common ancestor. We also resolve the controversy surrounding previous evidence of HGT in humans and provide at least 33 new examples of horizontally acquired genes. CONCLUSIONS: We argue that HGT has occurred, and continues to occur, on a previously unsuspected scale in metazoans and is likely to have contributed to biochemical diversification during animal evolution.This work was supported by the European Research Council (AdG233232).This is the final published version. It first appeared at http://genomebiology.com/2015/16/1/50

Determination of Water Content in Dehydrated Mammalian Cells Using Terahertz Pulsed Imaging: A Feasibility Study

This is the accepted version of the following article: Chau, D., Dennis, A. R., Lin, H., Zeitler, J. A., Tunnacliffe, A., ‘Determination of Water Content in Dehydrated Mammalian Cells Using Terahertz Pulsed Imaging: A Feasibility Study’, Current Pharmaceutical Biotechnology 17(2): 200-207, February 2016. Subject to 12 months' embargo. Embargo end date: 1 February 2017. The published manuscript is available at http://www.eurekaselect.com/136239/articleMammalian cells are involved in a range of biotechnological applications and more recently have been increasingly exploited in regenerative medicine. Critical to successful applications involving mammalian cells are their long-term storage and transport, for which cryopreservation in liquid nitrogen is the most frequently used strategy. However, cryopreservation suffers from high costs, difficulties in transport logistics and the use of undesirable additives (e.g. animal sera or DMSO). An alternative approach, proposed as low cost, low maintenance and process-compatible, is viable desiccation of mammalian cells. Several groups claim to have achieved this, but the extent of desiccation in the cell samples concerned is not always clear, in part because of difficulties in determining very low water content. Although several techniques exist that are frequently used to quantify the amount of water in samples (e.g. FTIR spectroscopy, thermogravimetric analysis (TGA), NMR spectroscopy), the complexity of sample preparation, as well as the costs and time constraints involved are disadvantageous. Here, we assess a novel, rapid and low cost technique, i.e. terahertz (THz) spectroscopy, for the quantification of water content within dehydrated mammalian cell samples.Peer reviewe