Multiple Buster transposons from hAT superfamily displaying transposition activities in mammal cells

TcBuster, a member of the Buster family within the hAT superfamily, has been engineered into an effective gene transfer tool for gene therapy applications. To diversify the toolkit available for efficient gene delivery, we conducted a bioinformatics analysis, which indicated that some Buster (BT) transposons exhibit signs of recent activity in Actinopterygii and Arthropoda species. Cell-based transposition assays demonstrated that endogenous transposases from Armadillidium nasatum (AnBT), Hyles vespertilio (HvBT), and Lota lota (LlBT) showed 47 %, 44 %, and 39 % transposition activity, respectively, in comparison to that of piggyBac transposons. Conversely, transposases from Carcinoscorpius rotundicauda (CrBT) and Larimichthys crocea (LcBT) presented minimal activity. Further assays confirmed that the 240 bp left and 126 bp right terminal sequences of the AnBT transposon are critical for maintaining transposition activity. In addition, AnBT exhibited the typical overproduction inhibition effect, reaching optimal activity at a 50 ng helper plasmid input, with both minimal (10 ng) and maximal (500 ng) doses of the donor plasmid. Notably, AnBT's transposition efficiency was 63 % compared to that of piggyBac at peak activity levels. This evidence suggests that AnBT could be a promising alternative gene delivery vector for gene therapy and transgenesis.