Aislamiento de cepas de traustoquitridios en la zona costera de Puerto Montt, Chile y evaluación de la producción de ácido docosahexaenoico (C22:6n-3, DHA)

Cuarenta y seis cepas que presentaron las característicasmorfológicas descritas para traustoquitridios fueron aisladasdesde muestras colectadas en cinco localidades de la zona costera de Puerto Montt, Chile, utilizando la técnica de polen de pino. Las 16 cepas que mostraron el perfil característico de tres bandas cuando el ADN fue amplificado con un conjunto de tres cebadores (FA1RA1, FA2RA2 y FA3RA3) diseñados para estos microorganismos(17), fueron cultivadas en medio líquido para evaluar la producción de ácido docosahexaenoico (C22:6n-3, DHA). El cultivo se realizó en matraces de Erlenmeyer agitados y la composición del medio basal fue: glucosa 10 g/L, extracto de levadura 4 g/L, en agua de mar diluida al 70%. Sólo 6 cepasprodujeron lípidos en los que se detectó DHA; los mayorescontenidos de DHA en los ácidos grasos totales y de DHA en la biomasa fueron 46,4% (cepa G4) y 36,2 mg/g (cepa M12-X1), respectivamente. El análisis de filogenia molecular basado en el alineamiento de la secuencia del gen que codifica para el ARN de la subunidad pequeña ribosomal (18S rRNA) confirmó que las tres cepas nativas que producen DHA pertenecen al phylum Labyrinthulomycota. Pruebas preliminares demostraron que es posible incrementar la concentración de biomasa (83%), el contenido de DHA en la biomasa (153%) y la concentración de DHA (71%) a través de la inclusión de glutamato monosódico en el medio de cultivo basal.

Alternative Splicing of RNA Triplets Is Often Regulated and Accelerates Proteome Evolution

Thousands of human genes contain introns ending in NAGNAG (N any nucleotide), where both NAGs can function as 3′ splice sites, yielding isoforms that differ by inclusion/exclusion of three bases. However, few models exist for how such splicing might be regulated, and some studies have concluded that NAGNAG splicing is purely stochastic and nonfunctional. Here, we used deep RNA-Seq data from 16 human and eight mouse tissues to analyze the regulation and evolution of NAGNAG splicing. Using both biological and technical replicates to estimate false discovery rates, we estimate that at least 25% of alternatively spliced NAGNAGs undergo tissue-specific regulation in mammals, and alternative splicing of strongly tissue-specific NAGNAGs was 10 times as likely to be conserved between species as was splicing of non-tissue-specific events, implying selective maintenance. Preferential use of the distal NAG was associated with distinct sequence features, including a more distal location of the branch point and presence of a pyrimidine immediately before the first NAG, and alteration of these features in a splicing reporter shifted splicing away from the distal site. Strikingly, alignments of orthologous exons revealed a ~15-fold increase in the frequency of three base pair gaps at 3′ splice sites relative to nearby exon positions in both mammals and in Drosophila. Alternative splicing of NAGNAGs in human was associated with dramatically increased frequency of exon length changes at orthologous exon boundaries in rodents, and a model involving point mutations that create, destroy, or alter NAGNAGs can explain both the increased frequency and biased codon composition of gained/lost sequence observed at the beginnings of exons. This study shows that NAGNAG alternative splicing generates widespread differences between the proteomes of mammalian tissues, and suggests that the evolutionary trajectories of mammalian proteins are strongly biased by the locations and phases of the introns that interrupt coding sequences.Damon Runyon Cancer Research Foundation (DRG 2032-09)National Science Foundation (U.S.). (no. 0821391)United States. National Institutes of Healt

Biotechnological alternatives for omega-3 polyunsaturated fatty acids production Alternativas biotecnológicas para la producción de ácidos grasos poliinsaturados omega-3

Fish oils are the main sources of omega-3 (ω3) polyunsaturated acids (PUFA) such as eicosapentaenoic (C20:5ω3) and docosahexaenoic (C22:6ω3) acids. World demand for ω3 PUFA shows an increasing trend mainly due to the growth of the aquaculture industry and also due to the increasing demand for specific PUFA used as food supplements. Bacteria, fungi, microalgae and thraustochytrids are biotechnotogical PUFA alternatives to fish oils. These sources are characterized by specific PUFA profiles whose productivity depends on strain and growth conditions. PUFA content in bacteria is low; microalgae synthesize mixtures of PUFA; fungi system productivity is low due to long fermentation times. In heterotrofic cultures of thraustochytrids high concentrations of PUFA can be obtained. Moreover, many strains are able to synthesize a single ω3 PUFA. The optimization of fermentation systems and the development of technology capable of large-scale production are needed in order to make these alternativ

Biotechnological alternatives for omega-3 polyunsaturated fatty acids production

Fish oils are the main sources of omega-3 (omega 3) polyunsaturated acids (PUFA) such as eicosapentaenoic (C20:5 omega 3) and docosahexaenoic (C22:6 omega 3) acids. World demand for omega 3 PUFA shows an increasing trend mainly due to the growth of the aquaculture industry and also due to the Increasing demand for specific PUFA used as food supplements. Bacteria, fungi, microalgae and thraustochytrids are biotechnological PUFA alternatives to fish oils. These sources are characterized by specific PUFA profiles whose productivity depends on strain and growth conditions. PUFA content in bacteria is low; microalgae synthesize mixtures of PUFA; fungi system productivity is low due to long fermentation times. In heterotrofic cultures of thraustochytrids high concentrations of PUFA can be obtained. Moreover, many strains are able to synthesize a single omega 3. PUFA. The optimization of fermentation systems and the development of technology capable of large-scale production are needed in order to make these alternatives, feasible

Chest pain CT in the Emergency Department: evaluating the coronary arteries even when not specifically asked for?

Background Computed tomography (CT) for excluding acute aortic syndrome (AAS) and pulmonary embolism (PE) simultaneously in patients with chest pain could be used to exclude coronary artery disease (CAD). Purpose To evaluate the frequency of further testing for CAD in patients receiving a CT in the emergency department (ED) for simultaneous evaluation for AAS and PE. Material and Methods This retrospective study was conducted over a three-year period including all patients with acute chest pain visiting our ED. All patients were included that received an electrocardiography (ECG)-gated CT of the entire chest enquiring simultaneously for AAS and PE. Those patients were followed up for 30 days after their initial ED visit whether they received further testing for CAD. Results Within the study period, a total of 157 patients with acute chest pain received a chest pain CT for simultaneous evaluation of both AAS and PE. Image quality was deemed sufficient to evaluate the coronary arteries in 80% of the patients. Thirty-seven patients (24%) underwent additional testing for CAD within 30 days of their ED visit, including catheter coronary angiography (n = 25), cardiac-stress single-photon emission-CT (n = 6), and cardiac magnetic resonance imaging (MRI) (n = 6). Conclusion Of patients presenting to the ED with acute chest pain who received a chest pain CT for simultaneous evaluation of AAS and PE, 24% had further imaging for CAD within 30 days of the initial ED visit. Immediate evaluation of the coronary arteries as part of a chest pain CT should be considered here for not delaying diagnosis