33 research outputs found

    FoxO and Stress Responses in the Cnidarian Hydra vulgaris

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    Background: In the face of changing environmental conditions, the mechanisms underlying stress responses in diverse organisms are of increasing interest. In vertebrates, Drosophila, and Caenorhabditis elegans, FoxO transcription factors mediate cellular responses to stress, including oxidative stress and dietary restriction. Although FoxO genes have been identified in early-arising animal lineages including sponges and cnidarians, little is known about their roles in these organisms. Methods/Principal Findings: We have examined the regulation of FoxO activity in members of the well-studied cnidarian genus Hydra. We find that Hydra FoxO is expressed at high levels in cells of the interstitial lineage, a cell lineage that includes multipotent stem cells that give rise to neurons, stinging cells, secretory cells and gametes. Using transgenic Hydra that express a FoxO-GFP fusion protein in cells of the interstitial lineage, we have determined that heat shock causes localization of the fusion protein to the nucleus. Our results also provide evidence that, as in bilaterian animals, Hydra FoxO activity is regulated by both Akt and JNK kinases. Conclusions: These findings imply that basic mechanisms of FoxO regulation arose before the evolution of bilaterians an

    Switchgrass (Panicum virgatum L.) polyubiquitin gene (PvUbi1 and PvUbi2) promoters for use in plant transformation

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    <p>Abstract</p> <p>Background</p> <p>The ubiquitin protein is present in all eukaryotic cells and promoters from ubiquitin genes are good candidates to regulate the constitutive expression of transgenes in plants. Therefore, two switchgrass (<it>Panicum virgatum </it>L.) ubiquitin genes (<it>PvUbi1 </it>and <it>PvUbi2</it>) were cloned and characterized. Reporter constructs were produced containing the isolated 5' upstream regulatory regions of the coding sequences (i.e. <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters) fused to the <it>uidA </it>coding region (<it>GUS</it>) and tested for transient and stable expression in a variety of plant species and tissues.</p> <p>Results</p> <p><it>PvUbi1 </it>consists of 607 bp containing <it>cis</it>-acting regulatory elements, a 5' untranslated region (UTR) containing a 93 bp non-coding exon and a 1291 bp intron, and a 918 bp open reading frame (ORF) that encodes four tandem, head -to-tail ubiquitin monomer repeats followed by a 191 bp 3' UTR. <it>PvUbi2 </it>consists of 692 bp containing <it>cis</it>-acting regulatory elements, a 5' UTR containing a 97 bp non-coding exon and a 1072 bp intron, a 1146 bp ORF that encodes five tandem ubiquitin monomer repeats and a 183 bp 3' UTR. <it>PvUbi1 </it>and <it>PvUbi2 </it>were expressed in all examined switchgrass tissues as measured by qRT-PCR. Using biolistic bombardment, <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters showed strong expression in switchgrass and rice callus, equaling or surpassing the expression levels of the CaMV <it>35S, 2x35S, ZmUbi1</it>, and <it>OsAct1 </it>promoters. GUS staining following stable transformation in rice demonstrated that the <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters drove expression in all examined tissues. When stably transformed into tobacco (<it>Nicotiana tabacum</it>), the <it>PvUbi2+3 </it>and <it>PvUbi2+9 </it>promoter fusion variants showed expression in vascular and reproductive tissues.</p> <p>Conclusions</p> <p>The <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters drive expression in switchgrass, rice and tobacco and are strong constitutive promoter candidates that will be useful in genetic transformation of monocots and dicots.</p

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Women's risk of repeat abortions is strongly associated with alcohol consumption: a longitudinal analysis of a Russian national panel study, 1994–2009

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    Abortion rates in Russia, particularly repeat abortions, are among the highest in the world, and abortion complications make a substantial contribution to the country’s high maternal mortality rate. Russia also has a very high rate of hazardous alcohol use. However, the association between alcohol use and abortion in Russia remains unexplored. We investigated the longitudinal predictors of first and repeat abortion, focussing on women’s alcohol use as a risk factor. Follow-up data from 2,623 women of reproductive age (16–44 years) was extracted from 14 waves of the Russian Longitudinal Monitoring Survey (RLMS), a nationally representative panel study covering the period 1994–2009. We used discrete time hazard models to estimate the probability of having a first and repeat abortion by social, demographic and health characteristics at the preceding study wave. Having a first abortion was associated with demographic factors such as age and parity, whereas repeat abortions were associated with low education and alcohol use. After adjustment for demographic and socioeconomic factors, the risk of having a repeat abortion increased significantly as women’s drinking frequency increased (P,0.001), and binge drinking women were significantly more likely to have a repeat abortion than non-drinkers (OR 2.28, 95% CI 1.62–3.20). This association was not accounted for by contraceptive use or a higher risk of pregnancy. Therefore the determinants of first and repeat abortion in Russia between 1994–2009 were different. Women who had repeat abortions were distinguished by their heavier and more frequent alcohol use. The mechanism for the association is not well understood but could be explained by unmeasured personality factors, such as risk taking, or social non-conformity increasing the risk of unplanned pregnancy. Heavy or frequent drinkers constitute a particularly high risk group for repeat abortion, who could be targeted in prevention efforts

    Advances in biotechnology and genomics of switchgrass

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    Switchgrass (Panicum virgatum L.) is a C(4 )perennial warm season grass indigenous to the North American tallgrass prairie. A number of its natural and agronomic traits, including adaptation to a wide geographical distribution, low nutrient requirements and production costs, high water use efficiency, high biomass potential, ease of harvesting, and potential for carbon storage, make it an attractive dedicated biomass crop for biofuel production. We believe that genetic improvements using biotechnology will be important to realize the potential of the biomass and biofuel-related uses of switchgrass. Tissue culture techniques aimed at rapid propagation of switchgrass and genetic transformation protocols have been developed. Rapid progress in genome sequencing and bioinformatics has provided efficient strategies to identify, tag, clone and manipulate many economically-important genes, including those related to higher biomass, saccharification efficiency, and lignin biosynthesis. Application of the best genetic tools should render improved switchgrass that will be more economically and environmentally sustainable as a lignocellulosic bioenergy feedstock
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