Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Detection of simian immunodeficiency virus RNA from infected rhesus macaques by the polymerase chain reaction

A rapid method for the detection of simian immunodeficiency virus (SIV) RNA from peripheral blood mononuclear cells (PBMC) of experimentally infected rhesus macaques by the polymerase chain reaction (PCR) is reported. The PCR was carried out with a complementary DNA (cDNA) template using 3 pairs of primers that were designed to anneal to homologous sequences in conserved regions of 3 molecular clones of SIV mac. The specificity of the primers was confirmed by performing the PCR with template DNA from the 3 molecular clones. SIV-specific RNA was detected from 30 and 50 infected PBMC/6.25 × 10 5 PBMC of two animals

Identification of Nucleotide Sequences for the Specific and Rapid Detection of Yersinia pestis

Suppression subtractive hybridization, a cost-effective approach for targeting unique DNA, was used to identify a 41.7-kb Yersinia pestis-specific region. One primer pair designed from this region amplified PCR products from natural isolates of Y. pestis and produced no false positives for near neighbors, an important criterion for unambiguous bacterial identification

Atraso do amadurecimento de banana 'Maçã' pelo 1-MCP, aplicado previamente à refrigeração Ripening delay of 'Apple' banana submitted to 1-MCP, prevoiously applied to refrigeration

O objetivo deste trabalho foi avaliar o efeito de diferentes períodos de exposição da banana 'Maçã' a 50 ppb de 1-MCP (0; 3; 6; 9; 12 e 24 horas) sobre sua vida pós-colheita e qualidade. Após exposição ao 1-MCP, os frutos verde-maturos foram armazenados por 30 dias em câmaras com temperatura de 13ºC &plusmn; 0,5 e umidade relativa de 95%. Em seguida, as bananas foram armazenadas à temperatura de 20ºC &plusmn; 1, até amarelecimento completo da casca. A exposição de banana 'Maçã' a 50 ppb de 1-MCP, por 9 horas, retardou em 7 dias o seu amadurecimento, em comparação a frutos não expostos ao 1-MCP, após 30 dias de armazenamento refrigerado (13ºC), sem prejuízos à sua aparência e composição química. A exposição de banana 'Maçã' a 50 ppb de 1-MCP, por 3 e 6 horas, não estendeu sua vida pós-colheita, tampouco alterou sua composição química. Embora a exposição de banana 'Maçã' a 50 ppb de 1-MCP, por 12 e 24 horas, tenha retardado o seu amadurecimento, promoveu alterações indesejáveis na casca do fruto. Logo, a aplicação de 50 ppb de 1-MCP, por 9 horas, antes da refrigeração, constitui-se numa alternativa viável para prolongar o período de comercialização da banana.<br>The aim of this work was to evaluate 'Apple' banana different periods exposure effect to 50 ppb of 1-MCP (0, 3, 6, 9 and 24 hours) on its postharvest life and quality. Mature-green fruits were stored for 30 days in chambers at 13ºC + 0,5 and relative humidity 95%, after exposure to 1-MCP. Then, the bananas were stored at 20ºC + 1 until peel complete yellowing. 'Apple' banana to 50 ppb of 1-MCP exposure during 9 hours delayed in seven days the fruit ripening, comparing to fruit control, after 30 days of cool storage (13ºC), without changing its appearance and chemical composition. The exposure of 'Apple' banana to 50 ppb of 1-MCP for 3 and 6 hours did not extend its postharvest life; neither changed its chemical composition. Although the exposure of 'Apple' banana to 50 ppb of 1-MCP for 12 and 24 hours has retarded its ripening, it promoted undesirable changes in the fruit peel. So, 1-MCP application for 9 hours at 50 ppb, before cool storage, is a viable alternative to extend banana's commercialization period

Efeito do tipo de corte e sanificantes no amaciamento de pequi (Caryocar brasiliense Camb.) minimamente processado Effect of the cut type and sanitizers on the softening of fresh cut pequi fruit (Caryocar brasiliense Camb.)

Frutos e hortaliças minimamente processados devem apresentar atributos de conveniência e qualidade do produto fresco. Com o presente trabalho, objetivou-se avaliar a influência dos sanificantes hipoclorito de sódio (NaClO) 50 ppm e 100 ppm e peróxido de hidrogênio (H2O2) 4% e 6%, sobre os processos envolvidos no amaciamento de pequi (Caryocar brasiliense Camb.) minimamente processado submetido a dois tipos de processamento: "caroço fatiado" e "caroço inteiro" e armazenado a 6 ± 1ºC e 90% a 95% UR, durante 15 dias. A cada três dias foram avaliados: perda de massa, firmeza, pectina total, pectina solúvel, atividade de pectinametilesterase (PME) e atividade de poligalacturonase (PG). O pequi minimamente processado apresentou perda de massa e decréscimo de firmeza ao longo do período de armazenamento, concomitante ao aumento da atividade da enzima poligalacturonase, bem como solubilização de substâncias pécticas. Não foi verificada atividade de PME no pequi minimamente processado avaliado. Os caroços fatiados apresentaram maior teor de pectina solúvel, do 3° ao 6° dia e atividade da enzima poligalacturonase, do 3° ao 12° dia de armazenamento, em relação aos caroços inteiros. A sanificação com NaClO 50 ppm e 100 ppm, H2O2 4% e 6% determinou maior solubilização péctica em pequis minimamente processados, ao longo do armazenamento, não sendo observada influência dos sanificantes sobre as variáveis firmeza, perda de massa e atividade de poligalacturonase.<br>Fresh cut fruits and vegetables should present convenience and quality features of the fresh produce. The present work aimed to evaluate the influence of the sanitizers 50ppm and 100ppm sodium hypochloride (NaClO) and 4% and 6% hydrogen peroxide (H2O2) on the involved processes in the softening of fresh cut pequi fruit (Caryocar brasiliense Camb.) submitted to two types of processing: "sliced stone" and "whole stone" stored at 6 ± 1°C and 90% to 95% of RH during 15 days. Every three the days mass loss, firmness, total pectin, soluble pectin, pectinmethylesterase activity (PME) and polygalacturonase activity (PG) were evaluated. The fresh cut pequi fruit presented mass loss, firmness decrease along the period of storage, concomitant to the increase of the activity of the enzyme polygalacturonase, as well as the solubilization of substances pectics. Activity of PME was not detected in fresh cut pequi fruit evaluated. The sliced stone showed, higher content of soluble pectins, from 3rd to 6th day and activity of the enzyme polygalacturonase, of 3rd to 12th day of storage, in relation to the whole stones. The sanification with NaClO 50ppm and 100ppm, H2O2 4% and 6% presented greater solubilization of pectic substances in fresh cut pequi fruit, during the storage, but it did not influence of the sanitizers on the variable firmness, loss of mass and activity of polygalacturonase