In vitro development of IVF-derived bovine embryos following cytoplasmic microinjection for the episomal expression of the IGF2 gene.

Important genomic imprinting changes usually occur following the in vitro production (IVP) of bovine embryos, especially in the imprinting pattern of components of the IGF system. This study aimed to evaluate the effects of a transient episomal overexpression of the IGF2 gene in bovine IVP embryos following embryo cytoplasmic microinjection (CMI) at the 1-cell stage on embryo survival, early and late developmental kinetics and morphological quality up to Day 7 of development. Selected cumulus-oocyte complexes (COCs) were matured and fertilized in vitro and subsequently segregated into six experimental groups: non-CMI control group and five CMI groups at increasing doses (0, 10, 20, 40 and 80 ng/µl) of a GFP vector built for the episomal expression of bovine IGF2. Zygote CMI was effective in delivering the expression vector into the ooplasm, irrespective of the groups, with 58% of positive GFP fluorescence in Day 7 blastocysts. Considering developmental rates and late embryo kinetics, the 10-ng/µl CMI vector dose promoted a lower blastocyst rate (10.4%), but for blastocysts at more advanced stages of development (93.0% blastocysts and expanded blastocysts), and higher number of cells (116.0 ± 3.0) than non-CMI controls (23.3%, 75.0% and 75.0 ± 6.8 were obtained, respectively). In conclusion, CMI at the 1-cell stage did not compromise subsequent in vitro development of surviving embryos, with the 10-ng/µl group demonstrating a possible growth-promoting effect of the IGF2 gene on embryo development, from the 1-cell to the blastocyst stage.

Live-cell imaging of Salmonella Typhimurium interaction with zebrafish larvae after injection and immersion delivery methods.

The zebrafish model has been used to determine the role of vertebrate innate immunity during bacterial infections. Here, we compare the in vivo immune response induced by GFP-tagged Salmonella Typhimurium inoculated by immersion and microinjection in transgenic zebrafish larvae. Our novel infection protocols in zebrafish allow live-cell imaging of Salmonella colonization.

Production of recombinant therapeutic proteins in genetically engineered animals: the dawn of a new era / Produção de proteínas terapêuticas recombinantes em animais geneticamente modificados: o surgimento de uma nova era

Background: The production of transgenic animals has been envisioned as a viable strategy to improve food quality, animal yield, and for the production of bioproducts that can be used for the benefit of the human and animal population. Transgenic animals have been used to improve production traits, to add value to animal products, to minimize the impact on the environment, to promote disease resistance, and most notably, to produce recombinant proteins in natural fluids, such as milk, that can be collected, purified and used as biomedical products (biopharming). This review aims to discuss past and recent technological advances in animal transgenesis, and the perspective for biopharming in Brazil.Review: Since the production of recombinant human insulin from Escherichia coli in the 1970s, continuous development of new platforms has allowed a significant expansion in the biopharmaceutical market. The animal platform has been shown to be highly competitive by adding value as low cost implementation, production and scale up, as well as high productivity of synthesized proteins. The expression of recombinant proteins in milk represents the most developed system for production of biopharmaceutical drugs in animals, with two approved biopharmaceuticals for human use: Atryn®, a recombinant antithrombin produced in the milk of goats, approved in 2006 by European Medicines Agency (EMA) and in 2009 by US Food and Drug Administration (FDA), and more recently, Ruconest®, a recombinant human C1 esterase inhibitor protein (C1INH) produced in the milk of rabbits, first approved by EMA in 2012, followed by the FDA approval in 2014. Transgenic animals have been produced by many strategies that have gradually evolved over the decades, including the use of embryo microinjection, viral vectors and transposable elements, sperm-mediated gene transfer, and cloning by somatic cell nuclear transfer (SCNT).[...](AU)

Production of recombinant therapeutic proteins in genetically engineered animals: the dawn of a new era / Produção de proteínas terapêuticas recombinantes em animais geneticamente modificados: o surgimento de uma nova era

Background: The production of transgenic animals has been envisioned as a viable strategy to improve food quality, animal yield, and for the production of bioproducts that can be used for the benefit of the human and animal population. Transgenic animals have been used to improve production traits, to add value to animal products, to minimize the impact on the environment, to promote disease resistance, and most notably, to produce recombinant proteins in natural fluids, such as milk, that can be collected, purified and used as biomedical products (biopharming). This review aims to discuss past and recent technological advances in animal transgenesis, and the perspective for biopharming in Brazil.Review: Since the production of recombinant human insulin from Escherichia coli in the 1970s, continuous development of new platforms has allowed a significant expansion in the biopharmaceutical market. The animal platform has been shown to be highly competitive by adding value as low cost implementation, production and scale up, as well as high productivity of synthesized proteins. The expression of recombinant proteins in milk represents the most developed system for production of biopharmaceutical drugs in animals, with two approved biopharmaceuticals for human use: Atryn®, a recombinant antithrombin produced in the milk of goats, approved in 2006 by European Medicines Agency (EMA) and in 2009 by US Food and Drug Administration (FDA), and more recently, Ruconest®, a recombinant human C1 esterase inhibitor protein (C1INH) produced in the milk of rabbits, first approved by EMA in 2012, followed by the FDA approval in 2014. Transgenic animals have been produced by many strategies that have gradually evolved over the decades, including the use of embryo microinjection, viral vectors and transposable elements, sperm-mediated gene transfer, and cloning by somatic cell nuclear transfer (SCNT).[...]

Pronuclear embryo yield in Canindé and Saanen goats for DNA microinjection.

The objective of this study was to examine the effect of donor breed on pronuclear-stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen-cloprostenol treatment. Forty-eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH-FSH-P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 µg of GnRH and they were hand-mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction.