The TRiP generated the VALIUM (Vermilion-AttB-Loxp-Intron-UAS-MCS) series of vectors for the incorporation of RNAi hairpins into attP landing sites (Ni et al. 2008, 2009, 2011).
Features of all VALIUM vectors
- vermilion as a selectable marker and an attB sequence to allow for phiC31 targeted integration at genomic attP landing sites. We chose vermilion rather than mini-white as the proper gene dosage of white has been found to be important in behavioral studies, a high-priority target application in the vector design.
- Two pentamers of UAS, one of which can be removed using the Cre/loxP system.
- hsp70 TATA promoter, which has been shown to be an effective promoter in UAS vectors.
- In addition to manipulating the number of UAS sequences, the level of RNAi knockdown can also be altered by using Gal4 lines of various strengths, rearing flies at different temperatures, or via coexpression of UAS-Dicer2 (Dietzl et al. 2007).
- Note that Dicer2 (Dcr2) is only effective with VALIUM1 and VALIUM10-series RNAi fly stocks, as Dcr2 processes long double-strand RNAs (dsRNAs) but not the short hairpin RNAs (shRNAs) used with other TRiP vectors.
For more details on knockdown vectors visit the TRiP plasmid vector sets page