381 PRODUCTION OF A TRANSGENIC PIGLET BY A NEW SPERM INJECTION TECHNIQUE

2006 ◽  
Vol 18 (2) ◽  
pp. 297
Author(s):  
H. Y. Yong ◽  
C. Murphy ◽  
A. Rieke ◽  
L. Lai ◽  
Y. Hao ◽  
...  

The technique for intracytoplasmic sperm injection (ICSI) has, until now, focused on scoring the tail of the sperm prior to catching and aspiration into the injection pipette. This is in spite of the fact that damage to the head would more closely simulate what occurs during normal fertilization. In addition, to aid in visualizing the injection process so that a reduced volume can be injected, the oocyte is generally centrifuged to clear a portion of the cytoplasm. Thus, with conventional ICSI, the sperm are immobilized with polyvinylpyrrolidone, repeatedly frozen and thawed, treated with DTT or Triton X-100, and severed between the head and tail; the oocyte is centrifuged or activated. All of the above treatments are designed to compensate for the intrinsic defects in conventional ICSI. Our objective was to use a modified ICSI procedure whereby aggressively motile sperm were captured onto the broken tip of an injection pipette and then injected into noncentrifuged oocytes. Damage to the head of the sperm occurred on the pipette or while pushed through the zona pellucida. These procedures are based on the work of Yong et al. 2003 Hum. Reprod. 18, 2390, where they achieved an improvement in development in vitro as compared to conventional methods. Ovaries were collected from prepubertal gilts, and oocytes were aspirated and matured in vitro. Sperm were collected from a transgenic boar carrying the green fluorescent protein (GFP) and frozen. After thawing, aggressively motile sperm were captured and injected through the zona pellucida and into the cytoplasm of the in vitro-matured oocytes. A total of 452 injected oocytes (43-171 oocytes per recipient) were surgically transferred into the oviduct of six surrogate gilts. Two gilts (33%) became pregnant. One gave birth to a healthy male piglet. GFP expression was observed in the nose and hooves by direct epifluorescent examination of the newborn piglet. This pattern of GFP expression is identical to that in non-ICSI-derived GFP pigs in this line. This result showed for the first time that this new sperm injection technique could be used for production of a viable transgenic piglet using in vitro-matured oocytes and frozen-thawed sperm.

2008 ◽  
Vol 35 (3) ◽  
pp. 243-253 ◽  
Author(s):  
Sean T. Glenn ◽  
Craig A. Jones ◽  
Li Pan ◽  
Kenneth W. Gross

Renin is responsible for initiating the enzymatic cascade that results in the production of angiotensin II, the major effector molecule of the renin-angiotensin system (RAS). Extensive information on the regulatory region of the renin gene has been derived by transient transfection studies in vitro, particularly using the As4.1 cell line. To verify key factors within the regulatory region of renin in vivo, homologous recombination was used to introduce a green fluorescent protein (GFP) cassette into exon one of the renin gene contained within a 240 kb bacterial artificial chromosome (BAC) to create a construct that has GFP expression controlled by the renin regulatory region (RenGFP BAC). Within the regulatory region of the RenGFP BAC construct we independently deleted the enhancer, as well as mutated the HOX-PBX site within the proximal promoter element. Transgenic lines were generated for each of these BAC constructs and GFP expression was analyzed throughout a spectrum of tissues positive for renin expression including the kidney, adrenal gland, gonadal artery, and submandibular gland. The results described within this manuscript support the interpretation that the renin enhancer is critical for regulating baseline expression where as the Hox/Pbx site is important for the tissue specificity of renin expression.


1999 ◽  
Vol 67 (4) ◽  
pp. 1812-1820 ◽  
Author(s):  
Maurizio del Poeta ◽  
Dena L. Toffaletti ◽  
Thomas H. Rude ◽  
Sara D. Sparks ◽  
Joseph Heitman ◽  
...  

ABSTRACT Synthetic green fluorescent protein (GFP) was used as a reporter to detect differential gene expression in the pathogenic fungusCryptococcus neoformans. Promoters from the C. neoformans actin, GAL7, or mating-type alpha pheromone (MFα1) genes were fused to GFP, and the resulting reporter genes were used to assess gene expression in serotype A C. neoformans. Yeast cells containing an integrated pACT::GFP construct demonstrated that the actin promoter was expressed during vegetative growth on yeast extract-peptone-dextrose medium. In contrast, yeast cells containing the inducible GAL7::GFP or MFα1::GFP reporter genes expressed significant GFP activity only during growth on galactose medium or V-8 agar, respectively. These findings demonstrated that the GAL7 and MFα1 promoters from a serotype D C. neoformans strain function when introduced into a serotype A strain. Because the MFα1 promoter is induced by nutrient deprivation and the MATα locus containing the MFα1 gene has been linked with virulence, yeast cells containing the pMFα1::GFP reporter gene were analyzed for GFP expression in the central nervous system (CNS) of immunosuppressed rabbits. In fact, significant GFP expression from the MFα1::GFP reporter gene was detected after the first week of a CNS infection. These findings suggest that there are temporal, host-specific cues that regulate gene expression during infection and that the MFα1 gene is induced during the proliferative stage of a CNS infection. In conclusion, GFP can be used as an effective and sensitive reporter to monitor specific C. neoformans gene expression in vitro, and GFP reporter constructs can be used as an approach to identify a novel gene(s) or to characterize known genes whose expression is regulated during infection.


Reproduction ◽  
2013 ◽  
Vol 145 (1) ◽  
pp. 97-108 ◽  
Author(s):  
Shahin Eghbalsaied ◽  
Kamran Ghaedi ◽  
Götz Laible ◽  
Sayed Morteza Hosseini ◽  
Mohsen Forouzanfar ◽  
...  

Transgenic mammals have been produced using sperm as vectors for exogenous DNA (sperm-mediated gene transfer (SMGT)) in combination with artificial insemination. Our study evaluated whether SMGT could also be achieved in combination with IVF to efficiently produce transgenic bovine embryos. We assessed binding and uptake of fluorescently labelled plasmids into sperm in the presence of different concentrations of dimethyl sulphoxide or lipofectamine. Live motile sperm displayed a characteristic punctuate fluorescence pattern across their entire surface, while uniform postacrosomal fluorescence was only apparent in dead sperm. Association with sperm or lipofection reagent protected exogenous DNA from DNase I digestion. Following IVF, presence and expression of episomal and non-episomal green fluorescent protein (GFP)-reporter plasmids was monitored in oocytes and embryos. We found no evidence of intracellular plasmid uptake and none of the resulting zygotes (n=96) and blastocysts were GFP positive by fluorescence microscopy or genomic PCR (n=751). When individual zona-free oocytes were matured, fertilised and continuously cultured in the presence of episomal reporter plasmids until the blastocyst stage, most embryos (38/68=56%) were associated with the exogenous DNA. Using anti-GFP immunocytochemistry (n=48) or GFP fluorescence (n=94), no GFP expression was detected in blastocysts. By contrast, ICSI resulted in 18% of embryos expressing the GFP reporter. In summary, exposure to DNA was an inefficient technique to produce transgenic bovine sperm or blastocysts in vitro.


2002 ◽  
Vol 22 (9) ◽  
pp. 3111-3120 ◽  
Author(s):  
Ming Zhao ◽  
Lyn Gold ◽  
Ann M. Ginsberg ◽  
Li-Fang Liang ◽  
Jurrien Dean

ABSTRACT The extracellular zona pellucida surrounding mammalian eggs is formed by interactions of the ZP1, ZP2, and ZP3 glycoproteins. Female mice lacking ZP2 or ZP3 do not form a stable zona matrix and are sterile. The three zona proteins are synthesized in growing oocytes and secreted prior to incorporation into the zona pellucida. A well-conserved furin site upstream of a transmembrane domain near the carboxyl terminus of each has been implicated in the release of the zona ectodomains from oocytes. However, mutation of the furin site (RNRR → ANAA) does not affect the intracellular trafficking or secretion of an enhanced green fluorescent protein (EGFP)-ZP3 fusion protein in heterologous somatic cells. After transient expression in growing oocytes, normal EGFP-ZP3 and mutant EGFP-ZP3 associate with the inner aspect of the zona pellucida, which is distinct from the plasma membrane. These in vitro results are confirmed in transgenic mice expressing EGFP-ZP3 with or without the mutant furin site. In each case, EGFP-ZP3 is incorporated throughout the width of the zona pellucida and the transgenic mice are fertile. These results indicate that the zona matrix accrues from the inside out and, unexpectedly, suggest that cleavage at the furin site is not required for formation of the extracellular zona pellucida surrounding mouse eggs.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 21092-21092
Author(s):  
K. Mori ◽  
Y. Yamaguchi ◽  
N. Sawada ◽  
K. Kondoh ◽  
S. Hayashi

21092 Background: In vitro studies in BC cell lines suggested antagonism between TAM and 5-FU. Thymidine phosphorylase (TP) activates X to 5-FU in tumors. X activity correlates with tumor TP concentrations in vivo. Methods: We studied antitumor efficacy of X + TAM in vivo and in vitro in human BC models. Nude mice were inoculated s.c. with estradiol, then MCF-7 cells 1 day later. When tumors were ∼300 mm3, mice received 6 weeks’ oral vehicle (control), X (d1–14 q21d) at MTD (539 mg/kg) or 2/3 MTD, and/or TAM at 100 or 30 mg/kg/d. We also analyzed impact of 5-FU and doxifluridine (5'-DFUR, an intermediate of X) + TAM on estrogen receptor (ER) signals in an in-vitro culture system. ER signals were monitored by expression of green fluorescent protein (GFP) in MCF-7 BC cells transfected with the estrogen-responsive element (ERE)-GFP gene (MCF-7-E10). GFP expression was induced in MCF-7-E10 cells in the presence of estradiol at 3 pM or BC tissue supernatant. Results: X at 2/3 MTD + TAM 30 mg/kg were significantly more active than the highest dose of X or TAM alone. Tumor TP concentrations were significantly higher in TAM- than vehicle-treated mice. In the ER signal system, GFP expression of MCF-7-E10 was reduced by 4-hydroxytamoxifen (4-OHT, active form of TAM) at 0.01 and 0.1 nM. When added to 4-OHT, 5-FU 0.3–30 μM or 5'-DFUR 3–10 μM reduced GFP expression more than either agent alone. In vitro, 5-FU and 5'-DFUR inhibited proliferation of MCF-7-E10 cells regardless of 4-OHT. Additive effects could not be confirmed as 4-OHT alone showed only marginal anti- proliferative activity at 0.01–0.1 nM. Conclusion: X and TAM are not antagonistic in this model. TAM may augment X activity via TP upregulation in BC tissues. TAM and X intermediates showed no clear antagonism in vitro in an ER signal system. All-oral X + TAM merits evaluation as combination therapy in breast cancer. [Table: see text]


2021 ◽  
Vol 9 (2) ◽  
pp. 13
Author(s):  
Bilal Ahmad Hakim ◽  
Vaishali Tyagi ◽  
Saurabh Kumar Agnihotri ◽  
Amar Nath ◽  
Ankit Kumar Agrawal ◽  
...  

Electroporation is an effective technique of transfection, but its efficiency depends on the optimization of various parameters. In this study, a simplified and efficient method of gene manipulation was standardized through electroporation to introduce a recombinant green fluorescent protein (GFP) construct as well as RNA-inhibitors in intact mouse follicles, oocytes and early embryos, where various electroporation parameters like voltage, pulse number and pulse duration were standardized. Electroporated preantral follicles were cultured further in vitro to obtain mature oocytes and their viability was confirmed through the localization of a known oocyte maturation marker, ovastacin, which appeared to be similar to the in vivo-derived mature oocytes and thus proved the viability of the in vitro matured oocytes after electroporation. Standardized electroporation parameters, i.e., three pulses of 30 V for 1 millisecond at an interval of 10 s, were applied to manipulate the expression of mmu-miR-26a in preantral follicles through the electroporation of miR inhibitors and mimics. The TUNEL apoptosis assay confirmed the normal development of the electroporated embryos when compared to the normal embryos. Conclusively, for the first time, this study demonstrated the delivery of exogenous oligonucleotides into intact mouse follicles, oocytes and embryos without hampering their zona pellucida (ZP) and further development.


2000 ◽  
Vol 66 (9) ◽  
pp. 4074-4083 ◽  
Author(s):  
Marcelo B. Aspiras ◽  
Karen M. Kazmerzak ◽  
Paul E. Kolenbrander ◽  
Roderick McNab ◽  
Neil Hardegen ◽  
...  

ABSTRACT Streptococcus gordonii is one of the predominant streptococci in the biofilm ecology of the oral cavity. It interacts with other bacteria through receptor-adhesin complexes formed between cognate molecules on the surfaces of the partner cells. To study the spatial organization of S. gordonii DL1 in oral biofilms, we used green fluorescent protein (GFP) as a species-specific marker to identify S. gordonii in a two-species in vitro oral biofilm flowcell system. To drive expression of gfp, we isolated and characterized an endogenous S. gordonii promoter,PhppA, which is situated upstream of the chromosomalhppA gene encoding an oligopeptide-binding lipoprotein. A chromosomal chloramphenicol acetyltransferase (cat) gene fusion with PhppA was constructed and used to demonstrate that PhppA was highly active throughout the growth of bacteria in batch culture. A promoterless 0.8-kb gfp(′gfp) cassette was PCR amplified from pBJ169 and subcloned to replace the cat cassette downstream of the S. gordonii-derived PhppA in pMH109-HPP, generating pMA1. Subsequently, the PhppA-′gfp cassette was PCR amplified from pMA1 and subcloned into pDL277 and pVA838 to generate the Escherichia coli-S. gordonii shuttle vectors pMA2 and pMA3, respectively. Each vector was transformed into S. gordonii DL1 aerobically to ensure GFP expression. Flow cytometric analyses of aerobically grown transformant cultures were performed over a 24-h period, and results showed that GFP could be successfully expressed in S. gordonii DL1 fromPhppA and that S. gordonii DL1 transformed with the PhppA-′gfp fusion plasmid stably maintained the fluorescent phenotype. Fluorescent S. gordonii DL1 transformants were used to elucidate the spatial arrangement ofS. gordonii DL1 alone in biofilms or with the coadhesion partner Streptococcus oralis 34 in two-species biofilms in a saliva-conditioned in vitro flowcell system. These results show for the first time that GFP expression in oral streptococci can be used as a species-specific marker in model oral biofilms.


2010 ◽  
Vol 22 (1) ◽  
pp. 369 ◽  
Author(s):  
M. El-Beirouthi ◽  
M. S. Albornoz ◽  
M. A. Martinez-Diaz ◽  
D. Zadworny ◽  
L. B. Agellon ◽  
...  

Apolipoprotein E (apo E) is a known risk factor for developing premature atherosclerosis and Alzheimer’s syndrome. The aim of this study was to create a pig model with reduced apo E levels using RNA interference (RNAi) and somatic cell nuclear transfer (SCNT) technologies. Three synthetic small interfering RNA targeting the porcine apo E mRNA were designed, and the knockdown efficiency was assessed in cultured porcine granulosa cells by real-time PCR. The observed apo E knockdown efficiency ranged from 45 to 82% compared with control cells, indicating the targeted degradation of apoE mRNA.A small hairpin RNA (shRNA) expressing vector was constructed in PRNAT.U6.Neo (Genscript Corp., Piscataway, NJ, USA) based on the most effective apo E RNAi sequence under the control of polymerase III (U6) promoter, and then introduced into fetal porcine fibroblast cells. Clones were selected by neomycin treatment and green fluorescent protein (GFP) expression. SCNT was performed using IVM oocytes collected from prepubertal gilts. Oocyte maturation and activation and embryo culture were performed as previously described (Nascimento et al. 2009 Reprod. Domest. Anim. in press). Embryos were cultured in vitro for 5 to 6 days, briefly exposed to fluorescent light to confirm GFP expression, and then surgically transferred into the uterus of recipient gilts. The recipient gilts were synchronized by daily oral administration of altrenogest (20 mg day-1; Regu-Mate®, Intervet, Millsboro, MD, USA) for 12 or 13 days, followed by 1000 IU of eCG injected in the last day of altrenogest treatment and 500 IU of hCG 72 h later. Pregnancy diagnosis was performed by ultrasonography at Day 20 to 25 after embryo transfer, and parturition was induced by injecting PGF2? (10 mg of dinoprost tromethamine; Lutalyse®, Pfizer Canada Inc., Montreal, QC, Canada) at Day 115 of pregnancy. Rates of cleavage (74.7%) and development to the blastocyst stage (37.2%) were comparable with that of embryos reconstructed with nontransfected cells from the same cell line. A total of 309 embryos were transferred to 5 recipients, of which 3 became pregnant and farrowed. Seven live and 1 stillborn piglets were delivered naturally. The presence of the introduced plasmid and the expression of the GFP transgene tag were confirmed by PCR in placental and umbilical tissues of all the piglets. Six cloned pigs have survived after weaning and exhibit no obvious morphological defects. The status of apo E gene expression is currently under investigation. Supported by a NSERC Discovery Grant to VB.


Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 72-79
Author(s):  
Vicente J.F. Freitas ◽  
Iana S. Campelo ◽  
Mirelly M.A.S. Silva ◽  
Camila M. Cavalcanti ◽  
Dárcio I.A. Teixeira ◽  
...  

SummaryThis study aimed to investigate the ability of disulphide-less crotamine (dLCr) to complex DNA and to evaluate whether the DNA–dLCr complex is capable of improving transfection in bovine embryos. Three experiments were performed to: (i) evaluate the formation and stability of the DNA–dLCr complex; (ii) assess the dLCr embryotoxicity by exposure of bovine embryos to dLCr; and (iii) assess the efficiency of bovine embryo transfection after microinjection of the DNA–dLCr complex or green fluorescent protein (GFP) plasmid alone (control). DNA complexation by dLCr after 30 min of incubation at 1:100 and 1:50 proportions presented higher efficiency (P < 0.05) than the two controls: native crotamine (NCr) 1:10 and lipofectamine. There was no difference between DNA–dLCr 1:25 and the controls. The DNA–dLCr complexation was evaluated at different proportions and times. In all, at least half of maximum complexation was achieved within the initial 30 min. No embryotoxicity of dLCr was verified after exposure of in vitro fertilized embryos to different concentrations of the peptide. The effectiveness of dLCr to improve exogenous gene expression was evaluated by microinjection of the DNA–dLCr complex into in vitro fertilized zygotes, followed by verification of both embryo development and GFP expression. From embryos microinjected with DNA only, 4.6% and 2.8% expressed the GFP transgene at day 5 and day 7, respectively. The DNA–dLCr complex did not increase the number of GFP-positive embryos. In conclusion, dLCr forms a complex with DNA and its application in in vitro culture is possible. However, the dLCr peptide sequence should be redesigned to improve GFP expression.


2005 ◽  
Vol 53 (10) ◽  
pp. 1215-1226 ◽  
Author(s):  
Andrea J. Mothe ◽  
Iris Kulbatski ◽  
Rita L. van Bendegem ◽  
Linda Lee ◽  
Eiji Kobayashi ◽  
...  

Green fluorescent protein (GFP) expression was evaluated in tissues of different transgenic rodents—Sprague-Dawley (SD) rat strain [SD-Tg(GFP)Bal], W rat strain [Wistar-TgN(CAG-GFP)184ys], and M mouse strain [Tg(GFPU)5Nagy/J]—by direct fluorescence of native GFP expression and by immunohistochemistry. The constitutively expressing GFP transgenic strains showed tissue-specific differences in GFP expression, and GFP immunohistochemistry amplified the fluorescent signal. The fluorescence of stem/progenitor cells cultured as neurospheres from the ependymal region of the adult spinal cord from the GFP SD and W rat strains was assessed in vitro. After transplantation of the cells into wildtype spinal cord, the ability to track the grafted cells was evaluated in vivo. Cultured stem/progenitor cells from the SD strain required GFP immunostaining to be visualized. Likewise, after transplantation of SD cells into the spinal cord, immunohistochemical amplification of the GFP signal was required for detection. In contrast, GFP expression of stem/progenitor cells generated from the W strain was readily detected by direct fluorescence both in vitro and in vivo without the need for immunohistochemical amplification. The cultured stem/progenitor cells transplanted into the spinal cord survived for at least 49 days after transplantation, and continued to express GFP, demonstrating stable expression of the GFP transgene in vivo.


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