PiggyBac is a class II transposon, which means that it moves by cutting and pasting, jumping from one place to another without leaving a copy. (In contrast, type I transposons move by copy and paste.) Since helper plasmids are only transiently transfected into host cells, they will be lost with time. With the loss of helper plasmids, the integration of transposons into host cell genomes becomes permanent. If these cells are transfected with helper plasmids again, the transposons could be removed from the genomes of some cells without footprints.
Creative BioMart's piggyBac gene expression vector system utilizes loxP stop loxP (LSL) box to achieve conditional activation of CRE mediated gene expression in mammalian cells and animals.
The LSL box contains loxP flanking triplet repeats of the SV40 polyadenylation sequence. The promoter selected by the user is located upstream of the box, while the gene of interest is located downstream of the box. In the absence of Cre recombinase, the cassette completely blocks the transcription of the target gene. After CRE is introduced into the cells carrying the vector, it is cut off and the promoter selected by the user is allowed to drive the transcription of the target gene.
The transposon-based piggyBac vector system consists of two vectors, both of which are engineered into E. coli plasmids.
Figure: Vector For loxP-STOP-loxP Insertion (left) and Inserting loxP-STOP-loxP (right).(Larson JD, 2019)
The promoter LSL box and target gene selected by users are cloned into this region. When both helper and transposon plasmids exist in the target cells, the transposase produced by the helper plasmids recognizes the two TRS on the transposon and inserts the flanking region containing the two TRS into the host genome. Insertion usually occurs at the host chromatid site containing the TTAA sequence, which repeats on both sides of the integrated fragment.
Stable gene activation: Cre recombinase has been used to permanently remove the 3x SV40 poly sequence which inhibited downstream transcription
Permanent integration of vector DNA: due to the loss of DNA over time, traditional transfection can transfer DNA to host cells almost instantaneously.
Technical simplicity: it is technically simple to deliver plasmid vectors into cells by conventional transfection
Very large cargo space: our transposon vector can hold about 30 KB of total DNA. The main chain of plasmid and transposon-related sequences only account for about 3 KB, leaving enough space to accommodate the user interested sequences.
Customers who need our assistance are more than welcome to contact us or submit an online inquiry. Our professional team will provide you with detailed guidance and solution ASAP.
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