영어
Injection of a linear transgene into male pronucleus has been widely used to produce Transgenic (Tg) mice. This approach however is inefficient and results in concatemerised transgene insertion and associated reduced protein expression from such insertions. The objective of this study is to develop active transgenesis method by using a piggyBac transposase plasmid DNA, and generate double transgene harboring transgenic mice. We examined the piggyBac transposase plasmid (pm- GENIE‐3) on its ability to produce transgenic animals with NaOH, HCl and FuGENE6 treated sperm followed by ICSI‐Tr, for its effectiveness in creating EGFP Tg mice, as judged by offspring epifluorescence. After these steps, we explored if the embryo development affects ICSI‐Tr efficiency by using substrate‐free media or aphidicolin. Moreover, we tested to determine if transgenesis is possible by directly injecting the DNA into the cytoplasm or into pronuclei. Finally, we attempted the introduction of two transgenes, such as EGFP and dsRED simultaneously in one transposon and the ability to generate double Tg mice by using NaOH treated sperm during ICSI‐Tr. The best results were obtained when sperm were treated with NaOH and co‐incubated with circular plasmid DNA of pmGENIE‐3. This resulted in Tg pups that could successfully express EGFP, with efficiencies of 37.9% of born animals being transgenic. Furthermore, the effectiveness of this method was proved by the production of Tg offspring from inbred strains of mice, such as C57BL/6, Balb/c and CD‐1 nude. While injection of DNA into the pronucleus or cytoplasm of one cell embryos, and delayed embryo development‐method were not as effective as ICSI‐Tr in producing Tg mice, they nevertheless proved successful. Finally, NaOH‐ICSI‐Tr successfully obtained Tg mice expressing both the EGFP and dsRED transgene. In conclusion, the current study developed an active form of NaOH‐ICSI‐Tr mediated transgenesis utilizing the piggyBac transposition machinery, and was successful in obtaining Tg mice which expressed simultaneously not only EGFP but also the dsRED transgene stably inserted in these animals.
