Although transgenic methods in mammals are inefficient, an easy and highly efficient transgenesis system using I-SceI meganuclease (intron-encoded endonuclease from S. cerevisiae) was recently described in Xenopus. The method consisted of injection into fertilized eggs of an I-SceI reaction mixture with a plasmid DNA carrying the transgene, flanked by the meganuclease recognition sites (pIS). In the present study, the effects of I-SceI on gene transfer were tested apparently for the first time in mammals, in particular, in cattle. Various conditions were evaluated, including three concentrations of the plasmid pIS Pax6egfp, carrying I-SceI recognition sites flanking egfp under Pax6 promoter and two injection times (before IVM and after IVF) of pIS CAGegfp, carrying I-SceI sites fanking egfp under CAG promoter. In addition, the quantity of transgene wa smeasured using quantitative polymerase chain reaction, and presence of transgene signals was evaluated using fluorescence in situ hybridization analysis. Transgene expression rates were higher (P minor to 0.05) for groups treated after IVF (79.1 per cent, 91/115 and 63.0 per cent, 75/119) than before IVM (32.6 per cent, 31/95 and 34.7 per cent, 33/95), with and without I-SceI, respectively. Interestingly, injectionwith pIS plus I-SceI after IVF increased frequency (P minor to 0.05) of nonmosaic transgene-expressing embryos (58.3 per cent, 42/72 vs. 29.7 per cent, 25/84) for pIS plus I-SceI and pIS alone. Based on fluorescence in situ hybridization analysis, injection with I-SceI increased (P minor to 0.05) the proportion of embryos with transgene signals in all blastomeres compared with pIS alone (44.0 per cent,11/25 vs. 6.9 per cent, 2/29) for pIS plus I-SceI and pIS alone. In addition, transgene copy number was numerically higher for the group treated with pIS plus I-SceI compared with pIS alone. In conclusion, I-SceI gene transfer increased transgene signals in bovine embryos.
Bevacqua, R. J.; Canel, N. G.; Hiriart, M. I.; Sipowicz, P.; Rozenblum, G. T.; Vitullo, A. D.; Radrizzani Helguera, M.; Fernández Martín, R. & Salamone, D. F. (2013).Simple gene transfer technique based on I - SceI meganuclease and cytoplasmic injection in IVF bovine embryos.Theriogenology,80, (2),p.104-113
10.1016/j.theriogenology.2013.03.017
Bevacqua, Romina Jimena,Canel, Natalia Gabriela,Hiriart, María Inés,Sipowicz, Pablo,Rozenblum, Guillermo Tomás,Vitullo, Alfredo Daniel, et al..2013. "Simple gene transfer technique based on I - SceI meganuclease and cytoplasmic injection in IVF bovine embryos".Theriogenology 80, no.2:104-113.
Recuperado de http://ri.agro.uba.ar/greenstone3/library/collection/arti/document/2013bevacqua