Efficient, fast and low-cost strategies for DNA extraction from different nucleated sheep cells

DNA extraction is usually the first step to perform molecular studies. This process can be nonviable due to genomic DNA (gDNA) extraction commercial kits prices. Furthermore, available DNA extraction protocols generally have high specificity, limiting their use to specific sources of biological material. In order to reduce costs, optimize time and laboratory logistics, besides to demonstrate a versatile protocol, the present study worked on an efficient DNA extraction protocol from somatic and non-somatic cells, using biological material from sheep as a model. For that, gDNA was extracted from whole blood, spermatozoa, and hair bulb cells, collected from three adult sheep, transported at 5ºC and stored at -20ºC until lab procedures. After extraction, gDNA concentration and purity were evaluated in a nano spectrophotometer. gDNA concentration from whole blood was greater (p < 0.05) than extracted from hair bulb cells, which in turn was superior (p < 0.05) than in spermatozoa. Also, gDNA from whole blood and, followed by, sperm showed greater (p < 0.05) purity when compared to gDNA of hair bulb cells. Adapting a gDNA extraction protocol, originally developed for bovine whole blood, enabled to obtain and isolate gDNA in different nucleated sheep cell

Genômica comparativa e reconstrução filogenética de papilomavírus

Os papilomavírus formam um grupo de vírus altamente diverso e específico que infectam mamíferos, aves e répteis. O conhecimento acerca da sua diversidade genética e evolução ainda é pobre, não existindo um cenário compreensivo que elucide as relações filogenéticas desses vírus. Assim, um estudo que visa ao entendimento da variabilidade genética entre os papilomavírus é fundamental para o aumento do conhecimento de sua complexa história evolutiva. Esse trabalho consistiu na análise de 53 sequências genômicas completas de papilomavírus, representando toda sua diversidade conhecida. Estudos de genômica comparativa foram realizados analisando o tamanho dos genomas; conteúdo gênico; variabilidade genética; estatística de códons; pressão seletiva; e recombinação. Regiões de baixa entropia foram utilizadas para a construção de ávores filogenéticas baseadas em quatro métodos diferentes. A metodologia empregada permitiu a identificação de regiões que são conservadas entre os papilomavírus que infectam hospedeiros diferentes, ajudando a entender suas relações evolutivas. Isto é muito importante porque, apesar da grande variação existente entre os genomas dos papilomavírus, fomos capazes de encontrar regiões que são claramente compartilhadas, apresentando baixos níveis de complexidade de informação, com o objetivo de fazer predições. Topologias coerentes foram obtidas com altos valores de confiança, apesar de não haver consistência em alguns nós internos. Esses resultados indicaram que tais regiões são bons marcadores para realização de inferências filogenéticas com menor custo computacional, resultando em um incremento na compreensão da diversificação dos papilomavíru

ANÁLISE DO TEMA VIROLOGIA EM LIVROS DIDÁTICOS DE BIOLOGIA DO ENSINO MÉDIO

A Virologia proporciona conhecimentos básicos e aplicados para serem utilizados no dia-adia das pessoas visando melhorar sua qualidade de vida no tocante à saúde coletiva. Entretanto, há uma carência muito grande de estudos que analisam esses conceitos nos livros didáticos do ensino médio. Esta pesquisa analisou os principais conceitos da Virologia nos livros didáticos de Biologia do ensino médio mais utilizados em escolas do município de Aracaju, Sergipe. A análise foi feita com ênfase na verificação de erros conceituais e em uma possível consideração do conhecimento prévio dos alunos. Os livros apresentaram problemas com relação aos conceitos empregados e à contextualização. Os resultados obtidos indicam a necessidade de reformulação e atualização desses recursos didáticos para o auxílio no ensino da Virologia

ANÁLISE DO TEMA VIROLOGIA EM LIVROS DIDÁTICOS DE BIOLOGIA DO ENSINO MÉDIO

A Virologia proporciona conhecimentos básicos e aplicados para serem utilizados no dia-a-dia das pessoas visando melhorar sua qualidade de vida no tocante à saúde coletiva. Entretanto, há uma carência muito grande de estudos que analisam esses conceitos nos livros didáticos do ensino médio. Esta pesquisa analisou os principais conceitos da Virologia nos livros didáticos de Biologia do ensino médio mais utilizados em escolas do município de Aracaju, Sergipe. A análise foi feita com ênfase na verificação de erros conceituais e em uma possível consideração do conhecimento prévio dos alunos. Os livros apresentaram problemas com relação aos conceitos empregados e à contextualização. Os resul tados obtidos indicam a necessidade de reformulação e atualização desses recursos didáticos para o auxílio no ensino da Virologia

Genomic constellations of RVA detected in Brazil from 1986 to 2016: a temporal and geographical distribution and occurrence of reassortments

Introduction: Species A rotavirus (RVA) infections are a major cause of severe gastroenteritis in children of <5 years worldwide. In Brazil, before vaccination, RVA was associated with 3.5 million episodes of acute diarrheal disease per year. Due to the segmented nature of their genomes, rotaviruses can exchange genes during co-infections, and generate new virus strains and new reinfections. Objective: To evaluate the genomic diversity of RVA isolated in Brazil in 30 years, between 1986 to 2016, to investigate possible changes in the frequency of genotype constellations before and after the implementation of the vaccine. Methods: In total, 4,474 nucleotide sequences were obtained from the Virus Variation Database. Genomic constellation was compared, and the proportion of rotavirus genotypes was analyzed by time and geographic region. Results: Our results showed that major known genotypes were circulating in the country during the period under analysis, with a prevalence of the G1P[8] Wa-like genotype, decreasing only in the period immediately after the introduction of the vaccine. Regarding the geographical distribution, most of our constellations, 62 (39.2%), and 50 (31.6%) were concentrated in the North and Northeast regions. Our analysis also showed the circulation of multiple strains during the periods when the DS-1-like and AU-1-like genotypes were co-circulating with the Wa-like genotype. Conclusion: Therefore, it is likely that inter-genogroup reassortments are still occurring in Brazil and so it is important to establish an efficient surveillance system to follow the emergence of novel reassorted strains that might not be targeted by the vaccine

Phenotypic and genotypic variations among three allopatric populations of Lutzomyia umbratilis, main vector of Leishmania guyanensis

Submitted by Adagilson Silva ([email protected]) on 2017-09-20T14:04:18Z No. of bitstreams: 1 26338469 2015 fre-phe.oa.pdf: 2163638 bytes, checksum: d8623ba27d611eec48f95113299aba1e (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-09-20T14:12:14Z (GMT) No. of bitstreams: 1 26338469 2015 fre-phe.oa.pdf: 2163638 bytes, checksum: d8623ba27d611eec48f95113299aba1e (MD5)Made available in DSpace on 2017-09-20T14:12:14Z (GMT). No. of bitstreams: 1 26338469 2015 fre-phe.oa.pdf: 2163638 bytes, checksum: d8623ba27d611eec48f95113299aba1e (MD5) Previous issue date: 2015-09-04Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, BrasilIn South America, Lutzomyia umbratilis is the main vector of Leishmania guyanensis, one of the species involved in the transmission of American tegumentary leishmaniasis. In Brazil, L. umbratilis has been recorded in the Amazon region, and in the state of Pernambuco, Northeastern region, where an isolated population has been identified. This study assessed the phylogeographic structure and size and shape differences of the wing of three Brazilian populations

Development of synthetic antigen vaccines for COVID-19

The current pandemic called COVID-19 caused by the SARS-CoV-2 virus brought the need for the search for fast alternatives to both control and fight the SARS-CoV-2 infection. Therefore, a race for a vaccine against COVID-19 took place, and some vaccines have been approved for emergency use in several countries in a record time. Ongoing prophylactic research has sought faster, safer, and precise alternatives by redirecting knowledge of other vaccines, and/or the development of new strategies using available tools, mainly in the areas of genomics and bioinformatics. The current review highlights the development of synthetic antigen vaccines, focusing on the usage of bioinformatics tools for the selection and construction of antigens on the different vaccine constructions under development, as well as strategies to optimize vaccines for COVID-19

Third-Generation Vaccines: Features of Nucleic Acid Vaccines and Strategies to Improve Their Efficiency

Gene immunization comprises mRNA and DNA vaccines, which stand out due to their simple design, maintenance, and high efficacy. Several studies indicate promising results in preclinical and clinical trials regarding immunization against ebola, human immunodeficiency virus (HIV), influenza, and human papillomavirus (HPV). The efficiency of nucleic acid vaccines has been highlighted in the fight against COVID-19 with unprecedented approval of their use in humans. However, their low intrinsic immunogenicity points to the need to use strategies capable of overcoming this characteristic and increasing the efficiency of vaccine campaigns. These strategies include the improvement of the epitopes&rsquo; presentation to the system via MHC, the evaluation of immunodominant epitopes with high coverage against emerging viral subtypes, the use of adjuvants that enhance immunogenicity, and the increase in the efficiency of vaccine transfection. In this review, we provide updates regarding some characteristics, construction, and improvement of such vaccines, especially about the production of synthetic multi-epitope genes, widely employed in the current gene-based vaccines