94 research outputs found

    Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae

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    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.Jennifer R. Bellon, Frank Schmid, Dimitra L. Capone, Barbara L. Dunn, Paul J. Chamber

    Single-embryo transfer reduces clinical pregnancy rates and live births in fresh IVF and Intracytoplasmic Sperm Injection (ICSI) cycles: a meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>It has become an accepted procedure to transfer more than one embryo to the patient to achieve acceptable ongoing pregnancy rates. However, transfers of more than a single embryo increase the probability of establishing a multiple gestation. Single-embryo transfer can minimize twin pregnancies but may also lower live birth rates. This meta-analysis aimed to compare current data on single-embryo versus double-embryo transfer in fresh IVF/ICSI cycles with respect to implantation, ongoing pregnancy and live birth rates.</p> <p>Methods</p> <p>Search strategies included on-line surveys of databases from 1995 to 2008. Data management and analysis were conducted using the Stats Direct statistical software. The fixed-effect model was used for odds ratio (OR). Fixed-effect effectiveness was evaluated by the Mantel Haenszel method. Seven trials fulfilled the inclusion criteria.</p> <p>Results</p> <p>When pooling results under the fixed-effect model, the implantation rate was not significantly different between double-embryo transfer (34.5%) and single-embryo transfer group (34.7%) (<it>P </it>= 0.96; OR = 0.99, 95% CI 0.78, 1.25). On the other hand, double-embryo transfer produced a statistically significantly higher ongoing clinical pregnancy rate (44.5%) than single-embryo transfer (28.3%) (<it>P </it>< 0.0001; OR:2.06, 95% CI = 1.64,2.60). At the same time, pooling results presented a significantly higher live birth rate when double-embryo transfer (42.5%) (P < 0.001; OR: 1.87, 95% CI = 1.44,2.42) was compared with single-embryo transfer (28.4%).</p> <p>Conclusion</p> <p>Meta-analysis with 95% confidence showed that, despite similar implantation rates, fresh double-embryo transfer had a 1.64 to 2.60 times greater ongoing pregnancy rate and 1.44 to 2.42 times greater live birth rate than single-embryo transfer in a population suitable for ART treatment.</p

    Origin and Examination of a Leafhopper Facultative Endosymbiont

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    Eukaryotes engage in intimate interactions with microbes that range in age and type of association. Although many conspicuous examples of ancient insect associates are studied (e.g., Buchneraaphidicola), fewer examples of younger associations are known. Here, we further characterize a recently evolved bacterial endosymbiont of the leafhopper Euscelidius variegatus (Hemiptera, Cicadellidae), called BEV. We found that BEV, continuously maintained in E. variegatus hosts at UC Berkeley since 1984, is vertically transmitted with high fidelity. Unlike many vertically transmitted, ancient endosymbioses, the BEV–E. variegatus association is not obligate for either partner, and BEV can be cultivated axenically. Sufficient BEV colonies were grown and harvested to estimate its genome size and provide a partial survey of the genome sequence. The BEV chromosome is about 3.8 Mbp, and there is evidence for an extrachromosomal element roughly 53 kb in size (e.g., prophage or plasmid). We sequenced 438 kb of unique short-insert clones, representing about 12% of the BEV genome. Nearly half of the gene fragments were similar to mobile DNA, including 15 distinct types of insertion sequences (IS). Analyses revealed that BEV not only shares virulence genes with plant pathogens, but also is closely related to the plant pathogenic genera Dickeya, Pectobacterium, and Brenneria. However, the slightly reduced genome size, abundance of mobile DNA, fastidious growth in culture, and efficient vertical transmission suggest that symbiosis with E. variegatus has had a significant impact on genome evolution in BEV

    mRNA accumulation in the Cajal bodies of the diplotene larch microsporocyte

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    In microsporocytes of the European larch, we demonstrated the presence of several mRNAs in spherical nuclear bodies. In the nuclei of microsporocytes, we observed up to 12 bodies, ranging from 0.5 to 6 μm in diameter, during the prophase of the first meiotic division. Our previous studies revealed the presence of polyadenylated RNA (poly(A) RNA) in these bodies, but did not confirm the presence of nascent transcripts or splicing factors of the SR family. The lack of these molecules precludes the bodies from being the sites of synthesis and early maturation of primary transcripts (Kołowerzo et al., Protoplasma 236:13–19, 2009). However, the bodies serve as sites for the accumulation of splicing machinery, including the Sm proteins and small nuclear RNAs. Characteristic ultrastructures and the molecular composition of the nuclear bodies, which contain poly(A) RNA, are indicative of Cajal bodies (CBs). Here, we demonstrated the presence of several housekeeping gene transcripts—α-tubulin, pectin methylesterase, peroxidase and catalase, ATPase, and inositol-3-phosphate synthase—in CBs. Additionally, we observed transcripts of the RNA polymerase II subunits RPB2 and RPB10 RNA pol II and the core spliceosome proteins mRNA SmD1, SmD2, and SmE. The co-localization of nascent transcripts and mRNAs indicates that mRNA accumulation/storage, particularly in CBs, occurs in the nucleus of microsporocytes

    Ancient fires enhance Amazon forest drought resistance

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    This is the final version. Available on open access from Frontiers Media via the DOI in this recordData availability statement: The datasets presented in this article are not readily available but the raw data supporting the conclusions of this article will be available under reasonable request to the authors. Requests to access the datasets should be directed to TF, [email protected] and fire reduce productivity and increase tree mortality in tropical forests. Fires also produce pyrogenic carbon (PyC), which persists in situ for centuries to millennia, and represents a legacy of past fires, potentially improving soil fertility and water holding capacity and selecting for the survival and recruitment of certain tree life-history (or successional) strategies. We investigated whether PyC is correlated with physicochemical soil properties, wood density, aboveground carbon (AGC) dynamics and forest resistance to severe drought. To achieve our aim, we used an Amazon-wide, long-term plot network, in forests without known recent fires, integrating site-specific measures of forest dynamics, soil properties and a unique soil PyC concentration database. We found that forests with higher concentrations of soil PyC had both higher soil fertility and lower wood density. Soil PyC was not associated with AGC dynamics in non-drought years. However, during extreme drought events (10% driest years), forests with higher concentrations of soil PyC experienced lower reductions in AGC gains (woody growth and recruitment), with this drought-immunizing effect increasing with drought severity. Forests with a legacy of ancient fires are therefore more likely to continue to grow and recruit under increased drought severity. Forests with high soil PyC concentrations (third quartile) had 3.8% greater AGC gains under mean drought, but 33.7% greater under the most extreme drought than forests with low soil PyC concentrations (first quartile), offsetting losses of up to 0.68 Mg C ha–1yr–1 of AGC under extreme drought events. This suggests that ancient fires have legacy effects on current forest dynamics, by altering soil fertility and favoring tree species capable of continued growth and recruitment during droughts. Therefore, mature forest that experienced fires centuries or millennia ago may have greater resistance to current short-term droughts.Coordination of Improvement of Personnel in Higher Education, Brazil (CAPES)Natural Environment Research Council (NERC)FAPESPRoyal SocietyNational Council for Science and Technology Development of Brazil (CNPq

    DENTISTS' KNOWLEDGE AND EXPERIENCE REGARDING LEPROSY IN AN ENDEMIC AREA IN BRAZIL

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    SUMMARY This study aims to analyze the dental surgeons' knowledge about leprosy and its ways of transmission, clinical characteristics and treatment, besides analyzing their experience with respect to diagnostic suspicion and case referrals. The study population comprised 242 dental surgeons working in the public dental service of the city of Cuiabá, Mato Grosso, Brazil. A self-applicable questionnaire containing questions about the dental surgeon's profile was used, including his/her knowledge on leprosy, as well as his/her practices concerning the disease. The results showed a predominance of female dental surgeons (65.7%), with ages ranging between 30 and 39 years old (43%) and professionals having six to 10 years of experience since graduation. Concerning their time working in the Unified Health System (SUS), the highest percentage of dental surgeons referred more than 10 years. Regarding the knowledge about the disease, 30.6% did not know the efficacy of the treatment of leprosy, 47% did not know the disease had to be notified compulsorily and only 8.3% had received information about leprosy at work. Besides that, most of them mentioned feeling little security when treating patients with leprosy (61.6%). Thus, dental surgeons' deficient knowledge on issues related to leprosy may be highlighted

    HISTOPLASMIN SURVEY IN HIV-POSITIVE PATIENTS: RESULTS FROM AN ENDEMIC AREA IN NORTHEASTERN BRAZIL

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    SUMMARY Background. Disseminated histoplasmosis is common in AIDS patients with advanced immunosuppression in Ceará, Northeastern Brazil. The goal of this study was to determine the prevalence of Histoplasma infection in patients with HIV/AIDS living in Fortaleza, the capital of Ceará. Methods. Intradermal tests with histoplasmin (mycelial phase) were performed in 161 HIV patients with CD4 ≥ 350 cells/mm 3 . Evidence of recent illness was evaluated with immunodiffusion (ID) tests in 76 of these individuals. Results. A total of 11.8% of patients reacted to histoplasmin and 2.63% had ID test positive to Histoplasma. The presence of mango trees (Mangifera indica) in the patient neighborhood (OR = 2.870; 95% CI = 1.081-7.617; p = 0.040) and past activity involving soil (OR = 2.834; 95% CI = 1.045-7.687; p = 0.045) or visits to a farm (OR = 3.869; 95% CI = 1.189-12.591; p = 0.033) were significantly associated with Histoplasma infection. Conclusions. Patients with HIV living in Fortaleza have an expressive prevalence of infection with Histoplasma
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