Application of PiggyBac in Transgenic Mice

Low transgene expression ratio in transgenic mice produced by male pronucleus injection of naked DNA into fertilized egg limits its application in various research purposes. In this paper, we used transposon piggyBac mediated transgenic method to prepare transgenic mice. The transgenic effi ciency and transgene expression ratio were compared with that in traditional transgenic mouse preparation method. The agouti gene was chosen as transgene, driven by PGK promoter and cloned into the piggyBac transposon cassette of plasmid pB232. The transgenic positive rate was 18.4%. 8 of 9 transgenic mouse founders showed agouti fur color phenotype which was much higher in ratio than that of traditional method. The results also showed that agouti gene ectopic expression could lead to obesity which was consistent with previous study. In conclusion, our results indicated that comparing with the traditional naked DNA pronucleus microinjection, piggyBac-mediated transgenic mouse approach could signifi cantly improve the expression of transgene in transgenic mice. Furthermore, using our report vector system, transgene expression positive transgenic mouse could be easily selected according to fur color.