Genetic transformation of the Brazilian BR 451 maize variety by the Agrobacterium tumefaciens method / Transformação genética da variedade brasileira de milho BR 451 pelo método da Agrobacterium tumefaciens

ABSTRACT: The asexually gene introduction by genetic engineering has brought enormous possibilities to innovate plant breeding. However, principally because of the low in vitro response, genetic transformation has been restricted to only certain genotypes of agronomically significant species. With the objective of establishing a protocol for genetically transforming the Brazilian BR 451 maize variety through Agrobacterium tumefaciens, it was studied the capacity of plant regeneration in vitro from embryogenic calli cultivated in three regeneration media, each having different growth regulators. It was also evaluated the temperature stress effect on the transformation of the immature embryos with A. tumefaciens EHA 101 containing the plasmid pTF102 with uidA and bar genes. The BR 451 variety embryos and those of the Hi-II hybrid (control) were exposed to three treatments applied as they were being infected with the agrobacteria (a) infection at 25°C; (b) infection at 40°C; (c) pretreatment at 40°C for 5 seconds followed by infection at 25°C. Transformation was determined by uidA gene expression and through the callus resistant to the herbicide Bialaphos® formation. Embryos infected at 40°C showed a higher degree of genetic transformation in the Hi-II, although the same was not noted in BR 451. When growth regulators were added to the culture medium the number of regenerated BR 451 plants showed no increase.

RESUMO: A introdução de genes de forma assexual por meio da engenharia genética tem ampliado as possibilidades do melhoramento genético vegetal. No entanto, devido principalmente a baixa resposta in vitro, a transformação genética tem se limitado a poucos genótipos das espécies de interesse agronômico. Visando estabelecer protocolo de transformação genética da variedade de milho BR 451 via Agrobacterium tumefaciens, foi estudada a capacidade de regeneração de plantas in vitro a partir de calos embriogênicos cultivados em três meios de regeneração contendo diferentes reguladores de crescimento. Também foi avaliado o efeito do estresse de temperatura na transformação de embriões imaturos com a A. tumefaciens EHA 101portadora do plasmídeo pTF102 que contém os genes uidA e bar. Para tal, três tratamentos foram aplicados aos embriões da variedade BR 451 e do híbrido Hi-II (controle) durante a infecção com a agrobactéria: (a) infecção em 25oC; (b) infecção a 40oC; (c) pré-tratamento de 40oC por cinco segundos seguido por infecção em 25oC. A transformação foi avaliada mediante a expressão do gene uidA e a formação de calos resistentes ao herbicida Bialaphos®. A infecção de embriões a 40oC aumentou a transformação genética em Hi-II, mas não em BR 451. A adição de reguladores de crescimento no meio de regeneração não incrementou o número de plantas regeneradas.

Deep sequencing analysis on transcriptomes of Edwardsiella tarda regulated by Eha following acidification / 中国人兽共患病学报

Our studies tried to demonstrate Eha (Et haemolysin activator) could regulate the resistance of the bacterium against acidification to survive in the macrophage and explain its underlying molecular mechanism.When the bacteria infected the macrophages at time intervals,intracellular survival rate in bafilomycin-treated macrophages was higher than that with untreated cells,and the rate of wild type ET 13 was higher than that of its eha mutant,respectively (P＜0.05).The survival rate of the wild type was higher than that of the mutant under acid treatment (P＜0.05).To determine the conditions that induced the highest eha expression,we constructed a pMP220-Peha LacZ plasmid and determined the lacZ expression under different conditions.After exposure of pH6.3 medium for 2 h time,we performed the whole transcriptomic profiles of the wild type and mutant by RNA-sequencing.We identified 147 differentially-expressed genes ([log2 ratio| ≥1),113 and 34 of which were significantly up-and down-regulated,respectively in the mutant,comparing with the wild type.These findings were validated by qRT-PCR.GO functional analysis revealed that these genes were divided into 25 categories,including the bacterial catalysis,cellular composition,combination,localization,metabolism,processing,and transportation.Based on the KEGG database,these genes were distributed in 55 pathways,such as two-component system,ABC transporters,and microbial metabolism in diverse environments.Overall,Eha is an important regulator to affect all kinds of target genes and pathways for E.tarda to adapt to an acid environment.These results could be helpful for further investigations of the mechanisms by which E.tarda survives in macrophages.

Enfermedad hepática grasa. Aspectos patológicos / Pathological aspects of fatty liver disease

En el hígado humano normal aproximadamente un 5% de su masa está compuesta por lípidos. Cuando tenemos aumento del depósito de grasa el término más utilizado es el de hígado graso o esteatosis e incluye el hígado graso no alcohólico (HGNA) y el hígado graso de etiología alcohólica (HGA), siendo aún la biopsia hepática considerada como el patrón de oro para determinar la severidad del daño hepático en cualquiera de estas entidades.

Expressão transiente do gene uidA em explantes foliares de Eucalyptus saligna Sm. transformado via Agrobacterium tumefaciens / Transient expression of uidA gene in leaf explants of Eucalyptus saligna Sm. transformed via Agrobacterium tumefaciens

O objetivo desse trabalho foi avaliar a influência do pré-cultivo de explantes foliares e do meio de cultura na ressuspensão de Agrobacterium tumefaciens para infecção dos explantes. Os meios MS/2 (50% da concentração de sais) e MS N/2 (50% da concentração de NH4NO3 e KNO3) + PGR (1,0µM de TDZ (thidiazuron) + 0,1 µM de ANA (ácido naftalenoacético)) foram testados na ressuspensão da bactéria para infecção dos explantes. O pré-cultivo consistiu da manutenção dos explantes em meio de cultura para formação de calos (MS N/2 + PGR) durante um dia, sendo o tratamento sem pré-cultivo consistituído dos explantes após a excissão dos mesmos. Os explantes foram mantidos no escuro a 25 ± 2ºC mediante a utilização de plástico preto. O delineamento usado foi o inteiramente casualisado com 20 explantes. Os experimentos foram repetidos duas vezes. O meio MS/2 promoveu resultados superiores (22,4%) comparado ao meio MS N/2 + PGR (14,5%) para a percentagem de área com expressão do gene uidA. Aos 7 dias de cultivo em meio seletivo, a percentagem de área expressando o gene uidA foi 1,6 no MS/2 e 0% para o MS N/2 + PGR. O pré-cultivo produziu resultados superiores aos encontrados sem pré-cultivo, atingindo 31,4% de expressão transiente e no tratamento sem pré-cultivo 2,1%. Após 7 dias de cultivo em meio seletivo, a percentagem de área de expressão dos explantes do tratamento com pré-cultivo permaneceu 4,8% e 0% para o tratamento sem pré-cultivo. Os resultados indicam que o précultivo e ressuspensão da bactéria em meio MS/2 aumentaram a eficiência da expressão transiente do gene uidA em explantes foliares de E. saligna.

The aim of this research was to evaluate the effect of the pre-culture of leaf explants and the effect of the culture medium for the Agrobacterium tumefaciens resuspension to the explant infection. The media, MS/2 (half strength) and MS N/2 (10.3 mM NH4NO3 and 9.4 mM KNO3) + PGR (1.0 µM TDZ (thidiazuron) and 0.1 µM NAA (1-Naphthaleneacetic acid)) were tested for the bacteria resuspension. The pre-culture consisted of the maintenance of the explants on culture medium for callus formation (MS N/2+PGR) during one day and the treatment without pre-culture consisted of the use of the explants after the excision of the same ones. At the end of the co-culture, the MS/2 promoted results superiors to the MS N/2+PGR, and the area percentage that presented expression of the gene uidA was of 22.4% compared at 14.5%. To the 7 days of culture on a medium with kanamycin, the area percentage expressing the gene uidA was 1.6 in MS/2 and 0% for the MS N/2+PGR. At the end of the co-culture, the pre-culture produced results superiors to the found in the treatment without pre-culture, reaching 31.4% of expression and in the treatment without pre-culture 2.1%. After 7 days of culture on a medium with kanamycin, the area percentage of explant expression of the treatment with pre-culture stayed 4.8% and 0% for the treatment without pre-culture. The results indicate that the pre-culture and the bacteria resuspension in MS/2 increase the efficiency of the transient expression of the gene uidA in leaf explants of E. saligna.

Progress in study of natural killer cells and their applications in hematological diseases: a report from the 2013 EHA annual meeting / 白血病·淋巴瘤

There were 17 literatures related to the clinical applications of natural killer cells in hematological diseases in the 18th annual meeting of the European Hematology Association (EHA).Here an overview of these literatures is given that helps to tnderstand how natural killer cells can be explored for future clinical interventions.

Advances in molecular pathogenesis and clinical therapy of multiple myeloma: a 2013 EHA annual meeting press releases / 白血病·淋巴瘤

Multiple myeloma (MM) is a genetically complex disease that is becoming more common in today' s aging population.In the 18th European Hematology Association (EHA) annual meeting,there were a number of key topics focusing on the development of MM from intraclonal heterogeneity,novel therapeutic agents,and relapse and refractory MM therapy,etc.

Genetic evolution and heterogeneity of multiple myeloma: a report from the 2013 EHA annual meeting / 白血病·淋巴瘤

Recent studies have shown that multiple myeloma (MM) is preceded by a premalignant state called monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM).Some of the genetic changes of MM are also present in MGUS and SMM,including chromosomal translocations,copy number changes,somatic mutations and so on.This article discusses the genetic heterogeneity.

EHA 2013: progress in study of cancer vaccination and its application in hematological malignancies / 白血病·淋巴瘤

There are 5 literatures related to the clinical applications of cancer vaccination in hematologieal malignancies in the 18th annual meeting of the European Hematology Association (EHA).This article provides an overview of these literatures that helps to understand how cancer vaccination can be explored for future clinical interventions.