Evidence of Food Safety in Relation to Cry Proteins in Genetically Modified Foods / Evidencias sobre seguridad alimentaria con relación a Cry proteínas en alimentos transgénicos

Abstract Developments in applying biotechnology to crops have generated strong ethical and social debates about its use. This study was aimed at reviewing epidemiological evidence regarding the consumption of genetically modified foods and the possible effects on human health, particularly certain insect-resistant crops in which isolated Bacillum thurigiensis Cry protein has been introduced. An in-depth review of databases was conducted for 2007-2019. Articles not referring to human health were excluded. In total, 1,350 were obtained and 118 were reviewed. As a result, it can be concluded that most studies have focused on chemical composition and in vitro or laboratory animal trials. Furthermore, the guiding principle of substantial equivalency, generally used today to evaluate potential health effects, should not replace rigorously evaluating products with nutritional, immunological, and toxicological trials. Lastly, this review demonstrates a lack of epidemiological evidence, and therefore, the safety of these foods cannot be conclusively determined based on evidence.

Resumen El desarrollo de la biotecnología aplicada a los cultivos ha generado fuertes debates éticos y sociales sobre su uso. El presente estudio tuvo por objetivo revisar las evidencias epidemiológicas existentes relacionando el consumo de alimentos genéticamente modificados, en particular aquellos provenientes de cultivos con resistencia a algunos insectos plagas en los que se han introducido proteínas Cry aisladas de Bacillum thurigiensis con probables daños o trastornos en la salud de las personas. Se realizó una revisión en profundidad en el periodo 2007 a 2019, en bases de datos. Se excluyeron aquellos artículos que no hacían referencia a salud humana. Se obtuvieron 1 350 y finalmente se revisaron 118. La revisión permitió concluir que la mayoría de los estudios existentes se centran en información respecto a la composición química y ensayos in vitro o en laboratorio con animales. Igualmente, que el principio rector de equivalencia sustancial hoy utilizado en forma generalizada para la evaluación de potenciales efectos en salud, no debería sustituir la necesidad de una evaluación rigurosa de los productos incluyendo ensayos nutricionales, inmunológicos y toxicológicos. Por último se comprueba también que la evidencia epidemiológica incluida es insuficiente por lo que lo que no es posible concluir a partir de ella, sobre la inocuidad de estos alimentos.

Shunt products of aminoansamycins from aas1 overexpressed mutant strain of Streptomyces sp. S35 / 中国天然药物

Constitutively expression of the pathway-specific activators is an effective method to activate silent gene clusters and improve natural product production. In this study, nine shunt products of aminoansamycins (1-9) were identified from a recombinant mutant strain S35-LAL by overexpressed the large-ATP-binding regulator of the LuxR family (LAL) gene aas1 in Streptomyces sp. S35. All the compounds showed no anti-microbial, anti-T3SS and cytotoxic activities.

Synthesis of pyrroloquinoline quinone by recombinant Gluconobacter oxydans / 生物工程学报

Pyrroloquinoline quinone (PQQ), an important redox enzyme cofactor, has many physiological and biochemical functions, and is widely used in food, medicine, health and agriculture industry. In this study, PQQ production by recombinant Gluconobacter oxydans was investigated. First, to reduce the by-product of acetic acid, the recombinant strain G. oxydans T1 was constructed, in which the pyruvate decarboxylase (GOX1081) was knocked out. Then the pqqABCDE gene cluster and tldD gene were fused under the control of endogenous constitutive promoter P0169, to generate the recombinant strain G. oxydans T2. Finally, the medium composition and fermentation conditions were optimized. The biomass of G. oxydans T1 and G. oxydans T2 were increased by 43.02% and 38.76% respectively, and the PQQ production was 4.82 and 20.5 times higher than that of the wild strain, respectively. Furthermore, the carbon sources and culture conditions of G. oxydans T2 were optimized, resulting in a final PQQ yield of (51.32±0.899 7 mg/L), 345.6 times higher than that of the wild strain. In all, the biomass of G. oxydans and the yield of PQQ can be effectively increased by genetic engineering.

Direct defense elicited by tetranychus urticae koch (acari: tetranychidae) in bt maize plants / Defesa direta elicitada por Tetranychus urticae koch (Acari: Tetranychidae) em milho Bt

Direct and indirect induced defense mechanisms against herbivores can be manifested in maize (Zea mays L.) plants. Furthermore, there are constitutive defenses in which plants continuously express resistance traces. In recent decades has increased the production of transgenic maize plants that constitutively express proteins with insecticide action (Bt maize). The increase of the use of transgenic maize cultivars with the Bt (Bacillus thuringiensis) gene demand studies that evaluate the impacts caused by this technology on plant defense mechanisms and their impact on non-targeted organisms, as the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). We tested the hypothesis that Bt maize plants (expressing Cry1F protein) would be capable of inducing direct defenses to T. urticae after being attacked by these mites. Thus, we used plants of a commercial maize hybrid (30F35 Hx - expressing Cry1F protein) and plants of its respective non-Bt isogenic line (control). We compared the survival and reproductive performances of T. urticae on plants of both lines that were previously infested with conspecifics and on plants that did not suffer pre-infestations. The previous infestation of maize plants by T. urticae did not impacted the survival and reproductive abilities of adult and immature forms of the conspecific in both genotypes. These results suggest that, Bt maize expressing the Cry1F insecticidal protein, does not interfere in the induction of direct defense by the T. urticae when compared with conventional maize plants.

Mecanismos diretos e indiretos de defesa induzida contra herbívoros podem manifestar-se em plantas de milho (Zea mays.). Além das defesas induzidas, existem as defesas constitutivas, nas quais as plantas expressam a resistência de forma contínua. Nas últimas décadas vem se difundindo a produção deplantas de milho geneticamente modificadas que expressam proteínas com ação inseticida de forma constitutiva (milho Bt). Com o crescente uso de cultivares de milho transgênico com o gene Bt (Bacillus thuringiensis), há uma demanda por estudos que avaliem os impactos causados por essa tecnologia sobre os mecanismos de defesa das plantas e seu impacto sobre organismos não alvo, como o ácaro-rajado Tetranychus urticae Koch (Acari: Tetranychidae). Testou-se a hipótese de que plantas de milho Bt (expressando a proteína Cry 1F) seriam capazes de induzir defesas diretas a T. urticae após o ataque por esses ácaros. Assim, foram utilizadas plantas de milhos híbridos comerciais (30F35 Hx expressando a proteína Cry 1F) e seu respectivo isogênico não-Bt (controle). Nós comparamos a sobrevivência e o desempenho reprodutivo de T. urticae em plantas de ambas as linhagens que foram previamente infestadas com coespecíficos e em plantas que não foram pré-infestadas. A infestação prévia de plantas de milho Bt por T. urticae nãoapresentou diferença nos padrões de sobrevivência de formas adultas e formas jovens do coespecífico em comparação com o milho convencional. Os resultados sugerem que, o fato de o milho Bt expressar a toxina inseticida Cry 1F, não interfere na indução de defesa direta pelo ácaro-rajado T. urticae quando comparado com plantas de milho convencional.

Transgênicos e o princípio de equivalência substancial / Transgenics and the principle of substantial equivalence

Objetivamos discutir os principais argumentos que estão envolvidos no debate sobre a cientificidade do Princípio de Equivalência Substancial (PES), que afirma serem os OGM quimicamente equivalentes aos organismos selecionados pelas técnicas tradicionais de melhoramento, não requerendo, portanto, estudos toxicológicos adicionais. Problematizamos a cientificidade do PES, especialmente no que diz respeito à questão propriamente química. De fato, o PES estrutura-se conceitualmente na comparação quantitativa entre alguns componentes químico-biológicos da planta transgênica e os da não transgênica. Nesse sentido, as análises químicas propostas não conseguem relacionar sozinhas os possíveis efeitos bioquímicos, toxicológicos e imunológicos dos alimentos transgênicos, pois o princípio restringe as análises à composição química, molecular e analítica dos transgênicos. Emerge assim o problema do locus da incerteza científica, seja como questão epistemológica, seja como questão normativa e moral.

We aim to discuss the main arguments involved in the debate on the scientificity of the Principle of Substantial Equivalence (PSE), which claims that GMOs are chemically equivalent to organisms selected by traditional breeding techniques and therefore do not require additional toxicological studies. We question the scientific character of the PSE, especially with regard to the chemical question itself. Indeed, the PSE is conceptually structured in the quantitative comparison between some chemical--biological components of the transgenic plant and those of the non-transgenic plant. In this sense, the proposed chemical analyses cannot by themselves assess the possi-ble biochemical, toxicological and immunological effects of transgenic foods, since the principle restricts the analysis to the chemical, molecular and analytical composition of transgenics. This gives rise to the problem of the locus of scientific uncertainty, whether as an epistemological question or as a normative and moral issue.

Cultivos genéticamente modificados: ¿son un riesgo para el ambiente y para la salud? / Are genetically modified cultures risky to environment and health?

La utilización de cultivos genéticamente modificados ha tenido en nuestro país y en el mundo una amplia acogida por parte de los productores agrícolas, pues ha significado una disminución de costos y un aumento de la producción. Uno de los temas más importantes del debate sobre la biotecnología aplicada a la agricultura se relaciona con los posibles riesgos sobre la salud humana y el ambiente que podrían generar los organismos vegetales genéticamente modificados (OVGM). Esta cuestión es la que origina las cuestiones regulativas, éticas y sociales actualmente en discusión

Genetically modified cultures have been well received by agricultural producers in our country and all round the world, because they generate greater benefits, less costs and increased production. Among the most important debated points over biotechnological application to agriculture is the possibility of risk that modified vegetable species may produce to human health. This question had generated multiple ethical, social and regulative worries

A utilização de cultivos geneticamente modificados tem atingido em nosso país e no mundo toda uma ampla acolhida da parte dos produtores agrícolas, pela diminuição dos custos e o acréscimo da produção. Um assunto dos mais importantes no debate sobre a biotecnologia aplicada à pecuária relaciona-se com os possíveis riscos sobre a saúde humana e o meio-ambiente que poderiam gerar os organismos vegetais genéticamente modificados (OVGM). Esta questão orienta aspectos de regulamentação, éticos e sociais que atualmente se discutem

GPo1 alkB gene expression for improvement of the degradation of diesel oil by a bacterial consortium

To facilitate the biodegradation of diesel oil, an oil biodegradation bacterial consortium was constructed. The alkane hydroxylase (alkB) gene of Pseudomonas putida GPo1 was constructed in a pCom8 expression vector, and the pCom8-GPo1 alkB plasmid was transformed into Escherichia coli DH5α. The AlkB protein was expressed by diesel oil induction and detected through SDS-polyacrylamide gel electrophoresis. The culture of the recombinant (pCom8-GPo1 alkB/E. coli DH5α) with the oil biodegradation bacterial consortium increased the degradation ratio of diesel oil at 24 h from 31% to 50%, and the facilitation rates were increased as the proportion of pCom8-GPo1 alkB/E. coli DH5α to the consortium increased. The results suggested that the expression of the GPo1 gene in E. coli DH5α could enhance the function of diesel oil degradation by the bacterial consortium.

Efficiency to Discovery Transgenic Loci in GM Rice Using Next Generation Sequencing Whole Genome Re-sequencing

Molecular characterization technology in genetically modified organisms, in addition to how transgenic biotechnologies are developed now require full transparency to assess the risk to living modified and non-modified organisms. Next generation sequencing (NGS) methodology is suggested as an effective means in genome characterization and detection of transgenic insertion locations. In the present study, we applied NGS to insert transgenic loci, specifically the epidermal growth factor (EGF) in genetically modified rice cells. A total of 29.3 Gb (~72x coverage) was sequenced with a 2 x 150 bp paired end method by Illumina HiSeq2500, which was consecutively mapped to the rice genome and T-vector sequence. The compatible pairs of reads were successfully mapped to 10 loci on the rice chromosome and vector sequences were validated to the insertion location by polymerase chain reaction (PCR) amplification. The EGF transgenic site was confirmed only on chromosome 4 by PCR. Results of this study demonstrated the success of NGS data to characterize the rice genome. Bioinformatics analyses must be developed in association with NGS data to identify highly accurate transgenic sites.

Improvement of butanol production by Escherichia coli via Tn5 transposon mediated mutagenesis / 生物工程学报

For engineering an efficient butanol-producing Escherichia coli strain, many efforts have been paid on the known genes or pathways based on current knowledge. However, many genes in the genome could also contribute to butanol production in an unexpected way. In this work, we used Tn5 transposon to construct a mutant library including 1 196 strains in a previously engineered butanol-producing E. coli strain. To screen the strains with improved titer of butanol production, we developed a high-throughput method for pyruvate detection based on dinitrophenylhydrazine reaction using 96-well microplate reader, because pyruvate is the precursor of butanol and its concentration is inversely correlated with butanol in the fermentation broth. Using this method, we successfully screened three mutants with increased butanol titer. The insertion sites of Tn5 transposon was in the ORFs of pykA, tdk, and cadC by inverse PCR and sequencing. These found genes would be efficient targets for further strain improvement. And the genome scanning strategy described here will be helpful for other microbial cell factory construction.

Construction of a recombinant Escherichia coli for high trehalose production / 生物工程学报

Trehalose, a compatible solute, is widely used in food, cosmetics, pharmaceutical products and organ transplantation. Nowadays, trehalose is mostly produced by enzymatic synthesis with many secondary products and lowpurity. In this study, high amount of trehalose was produced by recombinant E. ccli fermentation. First, a bifunctional trehalose gene TPSP was amplified from genome of C. hutchinscoii. Second, an expression vector pTac-HisA containing TPSP was constructed and transformed into the host E. coli. Expression of this bifunctional enzyme-TPSP converted glucose to trehalose. The result suggested that TPSP from C. hutchinsonji has been successfully expressed in E. ccoi. High amount of extracellular trehalose generated from glucose by whole-cell catalysis and After optimization, the production of trehalose in shake flasks was improved to 1.2 g/L and the relative conversion rate reached 21%. The production in bioreactor reached 13.3 g/L and the relative conversion rate reached 48.6%. It is the first time to realize the functional expression of the bifunctional enzyme-TPSP of C. hutchinsonii in E. coli and achieved the conversion form glucose to trehalose. This study laid a foundation for industrial large-scale production of trehalose.

Organismos genéticamente modificados, seguridad alimentaria y salud: trascendiendo la epidemiología y la salud pública / Genetically modified organisms, food safety and health: transcending epidemiology and public health

En las últimas décadas, los cambios en la agricultura y las innovaciones en biotecnología han modificado el panorama de la alimentación del planeta. Desde la década de los cincuenta, la revolución verde ha tenido un impacto dramático a nivel planetario y hoy en día temas como el desarrollo sostenible hacen parte de la agenda política mundial. Los Organismos Genéticamente Modificados han revolucionado la agroindustria y la biotecnología, y en la actualidad los cultivos de este tipo han crecido a un ritmo vertiginoso en varios países. Sin embargo, las promesas de erradicación del hambre y la inocuidad de estas nuevas bondades tecnológicas han creado profunda desconfianza y prevención tanto en la comunidad científica como en el público en general. Muchos abogan por el principio de precaución apelando a la incertidumbre científica dada la escasa evidencia de estudios epidemiológicos que evalúen efectos a largo plazo en la salud pública y al mismo tiempo, crece la polémica frente a un tema complejo de profundo interés general que impacta de manera relevante en diversas áreas del conocimiento...

In recent decades, changes in agriculture and biotechnology innovations have changed the landscape of food on the planet. From the fifties the green revolution has had a dramatic impact on a global level and today issues such as sustainable development are part of the global political agenda. Genetically Modified Organisms have revolutionized the agribusiness and biotechnology, and today these crops have grown at a rapid pace especially in countries like the US, Brazil and Argentina. However, the promises of eradicating hunger and progress of these new technological advantages have created some distrust and prevention both the scientific community and the general community. Many advocate the precautionary principle given by appealing to the limited evidence from epidemiological studies that evaluate long-term effects while scientific uncertainty, increasing debate on a complex issue that impacts deep general interest relevant way in several areas of knowledge...

Live bacterial vaccine vectors: An overview

Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology.

Estudio de libertad de operación para una línea genéticamente modificada de papa (Solanum tuberosum L. ) / Study of freedom to operate for a genetically modified potato (Solanum tuberosum L. ) line

Durante el desarrollo de los productos biotecnológicos son utilizados materiales y procesos, que pueden estar protegidos por derechos de propiedad intelectual. Para evitar problemas legales en su comercialización, se deben realizar estudios de libertad de operación. Este estudio se realizó sobre una línea genéticamente modificada (GM) de papa (Solanum tuberosum L.) derivada de la variedad Pastusa Suprema, que expresa el gene Cry1Ac de Bacillus thuringiensis, desarrollada por la Corporación de Ciencias Biológicas y la Universidad Nacional de Colombia, Sede Medellín. El punto de partida, fue la deconstrucción del producto, cuyo resultado fue la lista de materiales y procesos usados en el desarrollo del producto. Se buscaron en bases de datos nacionales e internacionales de acceso público, las solicitudes de patentes y patentes relacionadas. En el nivel internacional, se encontraron cuatro solicitudes de patentes y dieciocho patentes relacionadas, la mayoría de las cuales, no han sido solicitadas en Colombia. En el nivel nacional, se encontraron 13 solicitudes de patentes, que han caducado, han sido negadas, abandonadas, desistidas, o están en requerimiento. Se encontró que la variedad tiene registro comercial, pero no título de obtentor. También se examinaron documentos de las instituciones participantes, que contuvieran cláusulas sobre propiedad intelectual, y otros documentos de interés, como los acuerdos de transferencia de materiales (ATM). Se concluye que la libertad de operación puede estar afectada más por problemas detectados en los ATM y en la complejidad de los acuerdos interinstitucionales suscritos, que por los derechos de propiedad intelectual.

During the development of biotechnological products, some materials and processes are used, which can be protected by intellectual property rights (IPR's). In order to avoid legal problems related to their marketing, freedom-to-operate studies need to be done. This study was made on a genetically modified (GM) potato (Solanum tuberous L.) derived from variety "Pastusa Suprema", which expresses the gene cry1Ac from Bacillus thuringiensis, developed by Corporation for Biological Research (Corporación para Investigaciones Biológicas - CIB) and National University of Colombia at Medellín (Universidad Nacional de Colombia, sede Medellín). The starting point was the deconstruction of the product, whose result was the list of materials and processes used in the development of the new product. Patents and related applications were searched in national and international databases. At the international level, four applications and eighteen patents were found, most of which have not been applied for in Colombia. At the national levee, thirteen applications were found, which have expired, have been denied, abandoned, desisted or are currently on request. The plant variety has commercial registration but not breeder's certificate. Documents of the partaker institutions with IP clauses and other documents of interest, such as Material Transfer Agreements (ATM), were examined. It can be concluded that the freedom to operate might be affected for issues related to the ATMs and to the complexity of inter-institutional agreements, rather than for intellectual property rights.

Métodos para detecção de soja Roundup Ready® em grãos e produtos de soja por reação em cadeia da polimerase: revisão e análise crítica das práticas de validação / Methods for detecting the Roundup Ready® soy in soybeans and soy products by polymerase chain reaction: a review and critical analysis of current practices of validation

A informação sobre a origem transgênica de alimentos é muito relevante. Conforme a legislação brasileira e de outros países, o consumidor deve ser informado da natureza transgênica dos alimentos ou ingredientes que contenham ou que sejam produzidos a partir de organismos geneticamente modificados (OGM), com presença acima de um limite estabelecido. A necessidade de monitorar a presença e determinar o percentual de OGM em alimentos tem gerado uma constante demanda pelo desenvolvimento de metodologias capazes de detectar, identificar e quantificar o DNA exógeno. Entretanto, esses métodos necessitam ser validados para garantir confiabilidade aos resultados. No presente trabalho, a validação de métodos para detecção de soja Roundup Ready® em grãos e produtos de soja por reação em cadeia de polimerase foi contextualizada.Considerando-se atuais tendências em validação de métodos, os guias para validação de métodos específicos para OGM não contemplam todos os parâmetros necessários para avaliar a adequação aos propósitos de uso dos métodos, principalmente no caso de métodos qualitativos. Os parâmetros de desempenho mais frequentemente citados na literatura foram precisão (repetitividade), sensibilidade, linearidade e veracidade para metodologias quantitativas e taxas de sensibilidade e seletividade para qualitativas. Contudo, importantes parâmetros têm sido negligenciados nos processos de validação de métodos deste escopo analítico...

Rapid and high-throughput identification of recombinant bacteria with mass spectrometry assay / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To construct a rapid and high-throughput assay for identifying recombinant bacteria based on mass spectrometry.</p><p><b>METHODS</b>Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques were used to identify 12 recombinant proteins (10 of Yersinia pestis, 1 of Campylobacter jejuni and 1 of Helicobacter pylori). A classification model for the various phase of recombinant bacteria was established, optimized and validated, using MALDI-TOF MS-ClinProTools system. The differences in the peptide mass spectra were analyzed by using Biotyper and FlexAnalysis softwares.</p><p><b>RESULTS</b>Models of GA, SNN, and QC were established. After optimizing the parameters, the GA recognition model showed good classification capabilities: RC=100%, mean CVA=98.7% (the CVA was 96.4% in phase 1, 100% in phase 2, 98.4% in phase 3, and 100% in phase 4, respectively) and PPV=95%. This model can be used to classify the bacteria and their recombinant, which only requires 3.7×103 cells for analysis. The total time needed is only 10 min from protein extraction to reporting the result for one sample. Furthermore, this assay can automatically detect and test 96 samples concurrently. A total of 48 specific peaks (9, 16, 9, and 14 for the four stages, respectively) was found in the various phase of recombinant bacteria.</p><p><b>CONCLUSION</b>MALDI-TOF MS can be used as a fast, accurate, and high-throughput method to identify recombinant bacteria, which provide a new ideas not only for recombinant bacteria but also for the identification of mutant strains and bioterrorism pathogens.</p>

Ultrasonographic evaluation of hG-CSF transgenic goat conceptus / Avaliação ultrassonográfica de conceptos transgênicos para o hG-CSF

The objective of this study was to evaluate the development of transgenic (T) goat embryos and fetuses for human Granulocyte Colony Stimulating Factor (hG-CSF) by ultrasonography. Four pregnancies in non-transgenic (NT) goats were obtained after fertilization (either fixed-time artificial insemination or natural mating) using the T male for hG-CSF. Ultrasound examinations were carried out at 30, 40 (transrectal via), 50, 60, 90 and 120 days of pregnancy (transabdominal via). Some parameters were observed such as morphology, organogenesis and formation of skeletal fetuses, viability with cardiac activity and fetuses movements. Measurements were taken of the crown-rump length, diameter of embryonic vesicle, thorax, abdomen, umbilical cord and placentomes. After parturition, DNA testing was conducted in all offspring and 4 T and 2 NT kids were identified. The conceptus started their differentiation at 40 days. The heart was detected in all examinations and the heart chambers were assessed at 50 days. Gastric compartments, liver and kidneys were observed at 60 days, the same period that all bony structures were visualized. Average values of all evaluated parameters had a gradual increase with the progression of pregnancy. T and NT goat embryos and fetuses had a similar growth and all remained viable throughout the experimental period.

O objetivo deste estudo foi avaliar o desenvolvimento de embriões e fetos transgênicos (T) para o Fator Estimulante de Colôniasde Granulócitos humano (hG-CSF) por ultrassonografia. Quatro gestações em cabras não transgênicas (NT) foram obtidas pos fecundação (inseminação artificial em tempo fixo ou monta controlada) utilizando o bode T para o hG-CSF. Exames ultrassonográficos foram realizados aos 30, 40 (via transretal), 50, 60, 90 e 120 dias de gestação (via transabdominal). Alguns parâmetros foram observados como morfologia, organogênese e formação do esqueleto fetal, viabilidade por meio de atividade cardíaca e movimento fetal. As seguintes mensurações foram realizadas: comprimento crânio caudal, diâmetro da vesícula embrionária, do tórax, do abdomen, do cordão umbilical e dos placentomas. Após o parto, o exame por PCR foi conduzido em todas as crias e 4 T e 2NT foram identificadas. O concepto iniciou sua diferenciação aos 40 dias. O coração foi detectado em todos os exames e as câmeras cardíacas foram identificadas aos 50 dias. Compartimentos gástricos, fígado e rins foram observados aos 60 dias, o mesmo período que todas as estruturas ósseas foram visualizadas. Valores médios de todos os parâmetros avaliados tiveram um aumento gradual com o avanço da gestação. Embriões e fetos T e NT tiveram um crescimento similar e todos permaneceram viáveis durante o período experimental.

Anomalias en los comienzos de la transgenesis vegetal: intereses e interpretaciones en torno a las primeras plantas transgenicas / Anomalies in the early stages of plant transgenesis: interests and interpretations surrounding the first transgenic plants

Se presentan los orígenes de la transgénesis vegetal, analizando los experimentos que llevaron a la obtención de las primeras plantas transgénicas. Aquí se entrecruzan actores, prácticas e intereses que resultan emblemáticos de la biotecnología. Se trata, además, de un caso donde se pone en juego el consenso sobre el sentido de experimentos fundamentales. Estos sucesos permiten ilustrar parte de los conflictos en los que se involucran los organismos genéticamente modificados, pues en torno a estos primeros experimentos los científicos articularán representaciones distintas sobre la transgénesis vegetal, valorando de un modo distinto las anomalías que presentaban los primeros experimentos. De este modo, se analizan los intereses e interpretaciones en torno a los primeros experimentos con plantas transgénicas.

The origins of plant transgenesis are discussed and the experiments that led to the first transgenic plants are analyzed. This process involved a series of actors, practices and interests specific to biotechnology. Consensus about the meaning of fundamental experiments was also at issue here. These events illustrate some of the conflicts related to genetically modified organisms, since scientists had different responses to plant transgenesis at the time of the first experiments, and opinions of the anomalies in those experiments varied. Thus, this article analyzes the interests and interpretations surrounding the first experiments involving transgenic plants.

Applications of recombinant Pichia pastoris in the healthcare industry

Since the 1970s, the establishment and development of the biotech industry has improved exponentially, allowing the commercial production of biopharmaceutical proteins. Nowadays, new recombinant protein production is considered a multibillion-dollar market, in which about 25% of commercial pharmaceuticals are biopharmaceuticals. But to achieve a competitive production process is not an easy task. Any production process has to be highly productive, efficient and economic. Despite that the perfect host is still not discovered, several research groups have chosen Pichia pastoris as expression system for the production of their protein because of its many features. The attempt of this review is to embrace several research lines that have adopted Pichia pastoris as their expression system to produce a protein on an industrial scale in the health care industry.

Solving ethanol production problems with genetically modified yeast strains

The current world demand for bioethanol is increasing as a consequence of low fossil fuel availability and a growing number of ethanol/gasoline flex-fuel cars. In addition, countries in several parts of the world have agreed to reduce carbon dioxide emissions, and the use of ethanol as a fuel (which produces fewer pollutants than petroleum products) has been considered to be a good alternative to petroleum products. The ethanol that is produced in Brazil from the first-generation process is optimized and can be accomplished at low cost. However, because of the large volume of ethanol that is produced and traded each year, any small improvement in the process could represent a savings of billions dollars. Several Brazilian research programs are investing in sugarcane improvement, but little attention has been given to the improvement of yeast strains that participate in the first-generation process at present. The Brazilian ethanol production process uses sugarcane as a carbon source for the yeast Saccharomyces cerevisiae. Yeast is then grown at a high cellular density and high temperatures in large-capacity open tanks with cells recycle. All of these culture conditions compel the yeast to cope with several types of stress. Among the main stressors are high temperatures and high ethanol concentrations inside the fermentation tanks during alcohol production. Moreover, the competition between the desired yeast strains, which are inoculated at the beginning of the process, with contaminants such as wild type yeasts and bacteria, requires acid treatment to successfully recycle the cells. This review is focused on describing the problems and stressors within the Brazilian ethanol production system. It also highlights some genetic modifications that can help to circumvent these difficulties in yeast.

Influence of CXCR4 overexpressed mesenchymal stem cells on hematopoietic recovery of irradiated mice / 中国实验血液学杂志

This study was aimed to investigate the homing capacity of CXCR4 overexpressed mesenchymal stem cells (MSC) and their effect on hematopoietic recovery. The 293FT packaging cell line was transfected with the recombinant lentiviral vector LV-CXCR4-IRES-EGFP and LV-IRES-EGFP to produce lentivirus. Mouse MSC were then infected with viral supernatant. Male BALB/c mice were sublethally irradiated and then were injected intravenously with 5×10(5) MSC. General status and survival rate of mice were observed every day. On day 3, 7, 14, 21 and 28, peripheral blood samples were collected to calculate the number of white blood cells (WBC) and red blood cells (RBC), the ratio of reticulocyte to platelet, the number of platelet was detected by flow cytometry. The recovery of bone marrow and spleen was pathologically monitored. The proportion of MSC implantation was analysed by PCR. The results showed that the peripheral blood cells displayed the tendency of firstly increasing and then decreasing to their normal level. Generally, recovery of WBC level was earlier in mice infused with MSC (P < 0.05) . The histopathological examination of spleen and bone marrow showed a faster hematopoietic recovery in CXCR4-MSC group than the other two groups. And the donor MSC could be detected in the recipients on day 7, 14, 21 and 28. It is concluded that infusion of CXCR4-MSC enhances the implantation of hematopoietic stem cells and promotes hematopoietic recovery of the sublethally irradiated mice.