Cdh5-CatCh-IRES-lacZ transgenic mice express the calcium-translocating channelrhodopsin CatCh and lacZ under control of the Cdh5 locus promoter/enhancer regions within the BAC transgene. Cdh5-CatCh-IRES-lacZ mice from founder line B28-2 exhibit high expression levels of CatCh and lacZ in vascular endothelial cells (e.g., heart, lung, brain) - consistent with endogenous Cdh5. Additional details described further below.
CatCh is a calcium-translocating channelrhodopsin variant designed to have enhanced Ca2+ permeability, accelerated response kinetics and ~70-fold greater sensitivity to blue-to-green light (~450-530 nm; max 474 nm). Additional CatCh information is described below. For Cdh5-CatCh-IRES-lacZ transgenic mice, illumination of the CatCh molecule with this light in vascular endothelial cells is expected to result in reversible photostimulation of channel opening, calcium inflow and relaxation of the muscle.
The donating investigator reports that expression patterns appear to mimic the endogenous Cdh5 expression. Specifically, lacZ staining was observed in endothelial lined capillaries and vessels of the heart, lung and brain. Also, high levels of lacZ expression were observed in diaphragm vasculature. CatCh activation with light has not specifically been tested for Cdh5-CatCh-IRES-lacZ transgenic mice to date (July 2019) - although CatCh function has been shown to work as expected for other CHROMus lines (e.g., Stock Nos. 030334, 033344, etc.).
Mice hemizygous for the Cdh5-CatCh-IRES-lacZ transgene are viable and fertile with normal breeding, and no reported gross phenotypic abnormalities. To date (July 2019), it has not been attempted to make this strain homozygous.
This mouse model is available by way of a collaborative effort between Cornell/National Heart Lung Blood Resource for Optogenetic Mouse Signaling (CHROMus) and The Jackson Laboratory.
