MultiBac turns sweet

Figures & data

Table 1. Comparison of Baculovirus expression systems

	Plaque Purification	Increased protein quality	Automatation	Multi-gene expression
BacPAK6/BaculoGold	Yes	-	No	+
BacVector	Yes	++	No	+
Bac-to-Bac	No	-	Yes	-
flashBAC	No	++/+++	Yes	-
MultiBac	No	+	Yes	+++

Figure 1. The MultiBac vector system consists of an array of small synthetic DNA plasmids called acceptors and donors (A). Both classes contain a dual expression cassette (polh and p10) with eukaryotic polyadenylation signals (SV40 and HSVtk). Propagation of acceptors is driven by a regular origin of replication (ori^ColE1), whereas donors have a conditional origin (ori^R6Kγ) that requires special bacterial strains for replication. For selection in E.coli, acceptors contain a gentamycin resistance gene (Gn^R) and donors one antibiotic marker (Ab^R). For introduction in the MultiBac viral genome all vectors are equipped with a LoxP site and acceptors additionally with Tn7 transposition sites (Tn7L, Tn7R). Vectors are designed for an easy multiplexing of expression cassettes by the presence of specially designed restriction sites (B). Multigene constructs can futher be generated by fusing several donor vectors with one acceptor vector (C).

Figure 2. Multigene constructs based on acceptor vectors can be inserted in the MultiBac genome via the Tn7 transposition site. Within a second strategy expression cassettes can be inserted in the viral LoxP site in a Cre mediated reaction.

Figure 3. Schematic representation of the SweetBac platform. A donor vector containing open reading frames coding for Caenorhabditis elegans N-acetylglucosaminyltransferase II and the bovine β1,4-galactosyltransferase I was introduced in the LoxP site of a MultiBac genome resulting in SweetBac.