AAV with CMV-IVS promoter driven Cre Inducible VChR1-Venus

This AAV expresses DIO-VChR1-Venus driven by an ubiquitous CMV-IVS promoter.

The CMV-IVS promoter is about 1.1 kb in length and consists of the commonly used CMV promoter/enhancer and the intron (IVS) from beta-globin . The presence of intron elements was shown to give a higher level of transgene expression than that of the original CMV promoter/enhancer.

Volvox channelrhodopsin-1 (VChR1) is from the multicellular green alga Volvox carteri. VChR1 has a similar functionality as hChR2 but with a different excitation spectrum towards green light, and shows action potential firing with 589 nm light.

In the DIO scenario, the transgene of interest is inserted in reverse orientation relative to the 5' promoter and is flanked by oppositely oriented loxP and lox2272 sites. In the absence of Cre expression, the transgene will not be produced. In the presence of Cre expression, the transgene will be "FLip-EXchanged" or FLEXed, leading to expression of the transgene. This is due to a permanent Cre-mediated recombination/inversion of the flanked transgene. This arrangement is called DIO (double-floxed inverse ORF), Cre-ON, Flex-rev (reverse), Flex-ON/FlexON, or DIO-AAV/AAV-DIO (double-floxed inverse ORF in AAV).