Gt(ROSA)26Sor^{tm2(CAG-COP4*C128S*D156A*T159C,-tdTomato)Gfng}

The targeting construct is constructed by first using the Ai9 targeting vector modified to replace the tdTomato fragment with a SOUL-P2A-tdTomato cassette - from 5' to 3' - a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter, a FRT site, a loxP-flanked STOP cassette, the SOUL sequence (described below), a viral 2A oligopeptide, a tdTomato sequence, a woodchuck hepatitis virus post-transcriptional regulatory element, a bovine growth hormone polyA sequence (BGHpA) and an AttB/AttP-flanked PGK-frt-Neo-polyA cassette. This entire targeting vector was inserted between exons 1 and 2 of the Gt(ROSA)26Sor locus. The step-function opsin with ultra-high light sensitivity gene (SOUL; COP4*C128S*D156A*T159C) cDNA sequence encodes a channelrhodopsin-2 (ChR2; COP4 from the green alga Chlamydomonas reinhardtii) modified to have three amino acid substitutions that result in step function-like properties with extended channel open state (C128S/D156A) and enhanced photocurrent amplitudes (T159C). (J:292780)