Optimization of particle bombardment parameters for DNA delivery into the male flowers of banana

Biologia ◽  
2014 ◽  
Vol 69 (7) ◽  
Author(s):  
Fatemeh Mahdavi ◽  
Maziah Mahmood ◽  
Normah Noor

AbstractThe possibility of increasing the efficiency of banana transformation was investigated by particle bombardment of the male flowers of banana plants for constitutive expression of gfp gene. The effects of particle bombardment parameters, such as acceleration pressure, bombardment distance, chamber vacuum pressure, gold microcarrier size, gold quantity, DNA quantity, number of bombardments and pre-culture were examined. Single cauliflower-like bodies (CLBs) clusters, induced from meristemic parts of Musa sapientum cv. Nangka (AAB) male flowers, were bombarded by pCambia1304 plasmid carrying gfp gene driven by the CaMV 35S promoter. Optimal transient expression of green-fluorescent protein (GFP) was obtained when the three-day old cultured tissues were bombarded two times at 1100 psi helium pressure. However, the highest GFP expression was observed when 9 cm was applied as bombardment distance with 28 mmHg chamber vacuum pressure. Gold particle with 1 μm diameter at 60 μg/μL concentrations coated with 1.5 μg/μL of DNA have been used as the optimum bombardment parameter since GFP expression was significantly different compared to other conditions. Application of optimized condition proved effective for the generation of stable transgenic banana plants. PCR and southern blot analyses confirmed the presence and integration of gfp gene in genomic DNA of transformed plants. Transformation frequency achieved with the optimized protocol was 7.5% which was significantly higher than the conventional protocol.

Omni-Akuatika ◽  
2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Eni Kusrini ◽  
Alimuddin Alimuddin ◽  
Erma Primanita Hayuningtyas ◽  
Syuhada Restu Danupratama

Transfection and electroporation method shave a high possibility to apply towards transgenic production of small eggs size fish species.  This study aimed to examine the potential of transfection and electroporation methods to use for transferring a foreign gene into betta fish (Betta splendens) embryos using green fluorescent protein (GFP) gene as a model.  Fish were spawned naturally in the ratio of male: female was 1:1, then a total of 200 eggs were taken for each treatment.  Transfection was performed for 30 minutes (room temperature of about 25 °C) at two-cell stage of embryos using transfast reagent.  Transfection reaction consisted of 0.75 µL transfast reagent, 0.25 µL GFP expression vector (DNA concentration: 50 µg/µL) and 99 µL NaCl solution (concentration: 0,95%).  Electroporation was performed using 125 volt cm-1, 3 times pulse frequency at one second interval and pulse length of 7 micro seconds.  A volume of 800 µL GFP expression vector solution (DNA concentration: 50 µg/ µL) in PBS was used for electroporation.  The successful of foreign gene transfer was determined by PCR method with GFP specific primers.  The results showed that hatching rate of eggs in transfection treatment was 67.08%, while the electroporation was 72.09%.  Survival of larvae in transfection treatment was 73.00%, while the electroporation was 75.00%.  The results of PCR analysis showed that transfection method allowed 65% of the survived fish carrying GFP gene, whereas the electroporation method was 70%.  Thus, foreign gene transfer in betta fish can be conducted using the transfection and electroporation methods. 


2013 ◽  
Vol 25 (1) ◽  
pp. 315
Author(s):  
B. Koo ◽  
M. Kwon ◽  
J. Roh ◽  
J. Kim ◽  
T. Kim

The use of transgenic farm animals as bioreactors to address the growing demand for biopharmaceuticals, both in terms of increased quantity and greater number, represents a key development in the advancement of medical science. However, the potential for detrimental side effects as a result of uncontrolled constitutive expression of foreign genes in transgenic animals is a well-recognised limitation of such systems. Previously, using a tetracycline-inducible expression system, we demonstrated the induction of expression of a transgene encoding green fluorescent protein (GFP) in transgenic chickens by feeding with doxycycline, a tetracycline derivative; expression of GFP reverted to pre-induction levels when the inducer was removed from the diet (Kwon et al. 2011 Biochem. Biophys. Res. Commun. 410, 890–894). As a proof of principle study, however, quantitative assessment of expression was not possible, as only 1 G0 and 1 G1 transgenic chicken was obtained. In the current study, with 7 G2 transgenic chickens obtained from 1 G1 hen, we confirmed stable genomic integration of a single copy number of the transgene by Southern blot analysis. As we have observed in G1 transgenic chicken previously, all of the G2 transgenic chickens emitted a green fluorescence upon doxycycline feeding (50 mg kg–1 of formula feed). Fluorescence became detectable 4 days after starting doxycycline feeding, and maximum GFP expression was detected after 2 weeks. Removal of doxycycline from the diet after 14 days of induction feeding resulted in the return of external fluorescence to pre-induction levels after 39 days. Quantitative analysis of gene induction was done using protein and mRNA extracted from primary cultured cells derived from 6-day transgenic chicken embryos. The eggs were obtained by mating a nontransgenic wild-type hen with 1 of G2 transgenic roosters. Protein levels of GFP were analysed by immunoblot and quantified using a densitometer. In the absence of doxycycline, the amount of GFP per 1 µg of total protein was 0.2 ng. However, when the cells were treated with doxycycline for 6 days, the amount of GFP increased to 3.1 ng per 1 µg of total protein, which was 16-fold higher than that of the cells pre-treated with doxycycline. Switching to doxycycline-free medium after doxycycline induction resulted in significant abrogation of GFP expression in 6 days; the amount of GFP reduced from 3.1 to 0.5 ng, a 6.2-fold reduction. Transcription of the GFP gene was also assessed by Northern blot. The amount of GFP mRNA measured by band density increased as much as 20-fold (3.9/0.2) with 6 days of doxycycline induction and declined to 1/8 (3.9/0.5) when doxycycline was removed from the cell culture media for 6 days. The use of an inducible expression system that can be regulated by dietary supplementation could help mitigate the physiological disruption that can occur in transgenic animals as a result of uncontrolled constitutive expression of a transgene.


2005 ◽  
Vol 17 (2) ◽  
pp. 262
Author(s):  
B.C. Koo ◽  
M.S. Kwon ◽  
I. Jeon ◽  
W. Chang ◽  
T. Kim

One of the critical problems to be solved in transgenic animal production is non-controllable constitutive expression of the foreign gene, which usually results in serious physiological disturbances in the transgenic animal. To circumvent this problem, we constructed and tested two retrovirus vectors designed to express the GFP (green fluorescent protein) gene under the control of tetracycline-inducible promoters. To maximize the GFP gene expression at turn-on state, the WPRE (woodchuck hepatitis virus post-transcriptional regulatory element) sequence was also introduced into the retrovirus vector downstream of either the GFP gene or the sequence encoding rtTA (reverse tetracycline-controlled transactivator). Transformed cells derived from porcine fetus were cultured in the medium supplemented with or without doxycycline (tetracycline derivative) for 48 h, and induction efficiency was measured by comparing the GFP gene expression level using fluorometry and western blotting. Higher GFP expression was observed from the vector carrying the WPRE sequence at the 3′ side of the GFP gene, while tighter expression control (up to 20-fold) was obtained from the vector in which the WPRE sequence was placed at the 3′ side of the rtTA sequence. Encouraged with these data, we substituted the hPTH (human parathyroid hormone) gene for the GFP gene in the retrovirus vector. The porcine fetal fibroblast cells transformed by the modified retrovirus vector secreted hPTH into the medium under the tight control of doxycycline as observed in GFP expression. The resulting porcine cells secreting hPTH will be used in nuclear transfer experiment. This study was financially supported by the National Livestock Research Institute RDA (Suwon 441-350, Korea), ARPC (Agriculture R & D Promotion center, 2002–2005), and by grant No. R11-2002-100-01000-0 from the ERC program of the Korea Science & Engineering Foundation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danielle Weber-Adrian ◽  
Rikke Hahn Kofoed ◽  
Joseph Silburt ◽  
Zeinab Noroozian ◽  
Kairavi Shah ◽  
...  

AbstractNon-surgical gene delivery to the brain can be achieved following intravenous injection of viral vectors coupled with transcranial MRI-guided focused ultrasound (MRIgFUS) to temporarily and locally permeabilize the blood–brain barrier. Vector and promoter selection can provide neuronal expression in the brain, while limiting biodistribution and expression in peripheral organs. To date, the biodistribution of adeno-associated viruses (AAVs) within peripheral organs had not been quantified following intravenous injection and MRIgFUS delivery to the brain. We evaluated the quantity of viral DNA from the serotypes AAV9, AAV6, and a mosaic AAV1&2, expressing green fluorescent protein (GFP) under the neuron-specific synapsin promoter (syn). AAVs were administered intravenously during MRIgFUS targeting to the striatum and hippocampus in mice. The syn promoter led to undetectable levels of GFP expression in peripheral organs. In the liver, the biodistribution of AAV9 and AAV1&2 was 12.9- and 4.4-fold higher, respectively, compared to AAV6. The percentage of GFP-positive neurons in the FUS-targeted areas of the brain was comparable for AAV6-syn-GFP and AAV1&2-syn-GFP. In summary, MRIgFUS-mediated gene delivery with AAV6-syn-GFP had lower off-target biodistribution in the liver compared to AAV9 and AAV1&2, while providing neuronal GFP expression in the striatum and hippocampus.


2013 ◽  
Vol 95 (3) ◽  
pp. 319-329
Author(s):  
Atsushi Hirao ◽  
Tatsuo Kawarasaki ◽  
Kenjiro Konno ◽  
Satoko Enya ◽  
Masatoshi Shibata ◽  
...  

2012 ◽  
Vol 39 (9) ◽  
pp. 764 ◽  
Author(s):  
Gi-Ho Lee ◽  
Seong-Han Sohn ◽  
Eun-Young Park ◽  
Young-Doo Park

The chemical modification of DNA by methylation is a heritable trait and can be subsequently reversed without altering the original DNA sequence. Methylation can reduce or silence gene expression and is a component of a host’s defence response to foreign nucleic acids. In our study, we employed a plant transformation strategy using Nicotiana benthamiana Domin to study the heritable stability of the introduced transgenes. Through the introduction of the cauliflower mosaic virus (CaMV) 35S promoter and the green fluorescent protein (GFP) reporter gene, we demonstrated that this introduced promoter often triggers a homology-dependent gene-silencing (HDGS) response. These spontaneous transgene-silencing phenomena are due to methylation of the CaMV 35S promoter CAAT box during transgenic plant growth. This process is catalysed by SU(VAR)3–9 homologue 9 (SUVH9), histone deacetylase 1 (HDA1) and domains rearranged methylase 2 (DRM2). In particular, we showed from our data that SUVH9 is the key regulator of methylation activity in epigenetically silenced GFP transgenic lines; therefore, our findings demonstrate that an introduced viral promoter and transgene can be subject to a homology-dependent gene-silencing mechanism that can downregulate its expression and negatively influence the heritable stability of the transgene.


2018 ◽  
Vol 10 (4) ◽  
pp. 12
Author(s):  
Mahipal Singh ◽  
Xiaoling Ma

Dermal fibroblasts are useful for production of genetically engineered biologically active factors for development of cellular therapies and tissue engineering products for regenerative medicine. However, their transfection efficiencies using traditional non-viral methods are low and vary based on cell-type and species-specific differences. Using nucleofection technology, here we show that the transfection efficiency of primary fibroblasts established after 0-, 35-, and 65-days of postmortem storage of sheep skin tissues in a refrigerator was 59.49 % ± 9.66 %, 59.33 % ± 11.59 %, and 43.48 % ± 8.09 % respectively, as determined by analysis of green fluorescent protein (GFP) expression. 


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Liyue Wang ◽  
Kao Zhang ◽  
Hongyu Lin ◽  
Wenyan Li ◽  
Jiexia Wen ◽  
...  

Porcine reproductive and respiratory syndrome virus (PRRSV) is still one of the most important infectious diseases threatening the swine industry. To construct North American type II PRRSV infectious clone containing green fluorescent protein (GFP) gene, we amplify gfp gene, flanked by PRRSV Nsp2 gene fragments upstream and downstream, using overlap PCR method from pcDNA-EF1-GFP plasmid and FL12 plasmid containing PRRSV infectious genome as the templates. The Nsp2 fragment-flanked gfp gene was inserted into Nsp2 gene of the FL12 plasmid bySpeI andXhoI sites to generate PRRSV infectious recombinant plasmid (FL12-GFP) containing gfp gene. The recombinant PRRSV expressing GFP (PRRSV-GFP) was rescued in baby hamster kidney-21 (BHK-21) cells by transfecting PRRSV mRNA synthesizedin vitroand amplified in Marc-145 cells. The PRRSV-GFP infectivity and replication capacity were identified. Results showed that, by adopting overlap PCR strategy, the gfp gene was successfully inserted into and fused with PRRSV Nsp2 gene in the PRRSV infectious clone plasmid FL-12 to generate FL12-GFP plasmid. The recombinant PRRSV-GFP was generated through transfecting PRRSV mRNA in BHK-2 cells. Like its parental virus, the recombinant PRRSV-GFP maintains its infectivity to Marc-145 cells and porcine alveolar macrophages (PAMs). This study provides essential conditions for further investigation on PRRSV.


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